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Embedded Systems and Design & Development - Feb 23, 2026 | Morning | VisionAstraa EV Academy

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This content is an introductory lecture on embedded systems for e-mobility, focusing on the fundamental electrical and electronic principles necessary to understand electric vehicle (EV) architecture and control systems.

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Good morning to you all. So I am K Svin.

So I will be here dealing with uh

today's session. This session will go up

to Friday. So this topic mainly covers

on like uh your embedded systems which

is related to e-mobility.

So this is what the module is going to

be like. So to begin with I'm just uh

having an introduction. So this

introduction is about electrical vehicle

and its architecture. A small comparison

between ED and the traditional vehicles

vehicle comparison electric vehicle

system what is there inside an

electrical vehicle system and electric

vehicle control system what are the

control systems available within the

electrical vehicle system

we go with so this is an electrical

vehicle architecture so here

you can see our normal uh this mode this

is an internal combustion engine this is

is an hybrid. So you will be having a

battery pack inside it, right? So

whenever it is running an IC engine, so

your fuel will be like gasoline and this

will ignite this uh IC engine and uh

this will this ignition will run the

wheel and through which the electron

motor will be operating as a generator

and the motor drive will control its uh

control principle and it converts the

energy as required by the battery pack

and it will send it back. Similarly,

when it is running in battery mode, the

converter will convert the DC to AC as

required by the motor drive control and

it will feed back to motor and this will

run as motor and this will drive the

electric wheel system of the electric

vehicle. So here you can cannot charge

your battery whereas there is another

type that is where where you can charge

the battery. There will be some onboard

charger and through this onboard charger

you can charge the battery. Whereas in

this mode you cannot charge any battery.

The battery will be charged when the

vehicle once the vehicle is running as

an IC engine. So this is the basic

introduction. Maybe you are you may be

aware of it. So I'm just going with that.

that.

So if you just compare an IC engine with

the uh electric vehicle battery fed

vehicle you have any number of

components in an IC engine. And uh you

have only few number of components in an

electric vehicle. If you see here

uh though in IC engine or anything

you'll be having a battery to store its

energy and to start the motor. Similarly

here you don't have any IC. Though you

have IC engine you will be seeing

certain components which is related to

electric vehicle within the vehicle.

Whereas in a battery fitted vehicle you

cannot see any such component which is

related to IC engine inside this other

than the mechanical transmission system.

So the main components of electrical

vehicles are the motor and the power

control drives and the battery which is

giving power to it. Right? So with the

these components are more sufficient

enough to run a vehicle. So this is the

brief introduction comparison between

the a traditional EV and your uh IC

engine. Right? Now if you see the

conventional vehicle you have only fuel

tank and its engine. It is driven by

engines. Whereas you have another type

of vehicle that is hybrid electric

vehicle where you have fuel type as well

as your battery pack. Right? This is

driven by engines primarily motors secondary.

secondary.

Then you have another type that is

plug-in hybrid electric vehicles. Here

also you do have your uh IC engine as

well as your uh battery. Here the

primary motive is to run it as a motor

and engine secondary and completely

battery feded vehicles. Here you cannot

find any type of uh conventional IC

engine. You just find a battery pack, a

motor which is driving the wheel. Right?

So these are the

what you can say like evolution of uh

vehicle system. So this evolution of

vehicle system what is actually

eradicated is that the the conventional

uh this thing like uh engines and the

mechanical system which is being

connected from engines to this you have

many number of components within an IC

engine whereas you have a minimum number

of components in electrical vehicle

Okay. So in a vehicle if you see you

don't have uh any uh in electric vehicle

you don't have any mechanical components

like to transmit the power from one

place to another place. Whereas in if

you see an electrical vehicle you cannot

find any mechanical system you can find

only a ydriven wired driven uh

connections. So it is all done through

wire connections. So we are we generally

term it as harnessing. So we plan the

wire system. From the wire system what

you can see is that you can just

transmit one form of energy to the other

form. The energies are transmitted by

means of your wires or you'll be having

certain chips. Right? So using that only

the powers are being distributed and

transmitted. Right? So this is the

advantages and disadvantages between the

different types of vehicles right. So if

you take a electrical vehicle system

right so this is an electrical vehicle

system in an electrical vehicle system

as a component you see uh energy storage

system embedded system electronics and

motors right so first to begin with this

is energy storage so this is what the

fueling of vehicle system is right so

here you have batteries or ultra

capacitors the capacitors and battery feed

feed

Then one the required voltage and

current that components of electrical

vehicles require right. Next you have

embedded system. So in this embedded

system you have sensors, circuit and

processes. So what these sensors,

circuits and processes actually do? Okay

that I will tell you at this end of this

slide. Next electronics. So electronics

are nothing but semiconducting devices.

So these electronics have power

electronics as well as digital

electronics everything is there. So

these power electronics actually serves

as the driving force of the engine. The

engine is nothing but your motor. Right?

So the motors are the primary component

of the electrical vehicle system. Why

the motors are called as the primary

system means they actually transmit the

required power for the vehicle system to

the wheel. This makes actually the wheel

to rotate. That means this makes the

vehicle system to displace from one

point to another point. If you want to

move from one point to another point

that is done only by means of motor.

Okay. That motor is controlled through

this electronic devices. So in which way

the motor has to be controlled that is

done by this electronic circuits. So in

whichever way you want to control the

motor you cannot directly apply it to

the motor. You have to apply it through

this electronic devices only. You cannot

directly control the motor. Is that

clear? So if this motor has to be

controlled, that is if your vehicle has

to be controlled, you have to control

the motor. And if you want to control

the motor, you have to ultimately depend

upon the control of this electronic

circuits. So you cannot direct imply

anything with respect to the motor

control. You have to you have to

actually control the switches and its

power system and you have to control the

flow of this current and voltages by

means of this circuit and that will

imply upon the motor. Is that clear? So

if I want to control these electronic

devices then what I have to do because

as you see these electronic devices are

concealed. You cannot give any sorts of

supply into it. Just what you can do is

you can just give a primary electric

supply to the semiconducting devices and

get the output through some wires. So

this is what you can do. But every

system is concealed. So with this

electronic devices only all the

components of electrical vehicle has to

be communicated and it has to transmit

the informations from one one component

to the other component. Who will do that

and how we will do that? For that only

we have this embedded systems. So what

you can see is that this embedded system

serve as the nervous system of the

electrical vehicle system. This controls

and gives signal from one point of the

electrical vehicle to the other point.

And moreover by having everything in a

embedded system. So what is actually an

embedded system? Embedded system means

it's very simple. You have electronic

components right? You have electrical

components. So this has to be connected.

Okay. How this has to be connected? This

has to be connected through wires. So

you have wires and you connect the

available electronic components and

available electrical components with any

mechanically controlled equipments which

is available within the vehicle. Say let

us take an example of a window. Okay.

Window mirror. So the mirror has to rise

up and it has to rise down according to

your switches what you give. So you have

a manual switch and that manual switch

has to actually give the signal to the

window just it has to rise or up or

down. Okay. So we will be giving an

input as a power switch. Right? You

cannot give an information like you rise

up you rise down. You just give one

button as a press and one button as

unpressed. So that signal that signal

has to be converted into different way

so that the mirror will actually go up

and come down. So that will be done by

means of this sensors and the circuits

and the processor which you are doing.

So I can also do that by means of

electronics. So in embedded system you

all found you all find whatever you

found is that whatever you see in an

electronic devices. So if you see a

electronic devices you'll be having a

number of components. For example, if

you just open your CPU or your mobile

phone or any TV, any electronic devices

you just open, you found find a

motherboard. In that motherboard, you

have any number of components. So in

this n number of components has to

communicate one with other. But if I use

a wire, there is a high chances of

getting loosening of wire during

operation or there may be any circuit

fault. I cannot follow it. So following

that through a wire connection is very

very difficult. So what I do is that I

just make it into a form of a small

layout layout chip. So that board will

actually have the circuit in within it

and over which I will embed all the type

of electronic devices and I will connect

it through by means of any IC or

processor. So this is actually called as

the embedded system. So this embedded

system serves as the nervous system for

entire vehicle system. It actually

connects the battery with electronicses

and motor with electronics and battery

with motor. So all the influences and

all the component integration and the

communication is done by means of this

embedded system. So this is the

importance of embedded system in an

electrical vehicle system. So here in

this session we are going to see about

these things only right.

So if you take an electric vehicle

system architecture. So this is the

skeleton diagram of a electrical vehicle

system. So this select this skeleton

model what it shows is that you have a

high voltage battery and its management

system that is connected to a power

electronic controller devices and you

have a V uh motor that divides actually

the transmission system. So from battery

you are giving a power and that is being

transmitted to the motor and this motor

converts this electrical energy to a

mechanical energy and transmitted to the

wheel. Right? This is the skeleton model

of electric system. This is most common

for all type of vehicle. Now this this

scenario this marked region is called as

a power electronics and HV system. This

will include that name. Whereas here

this is this we will be calling as as

power train and performance level

system. Right? If you take the control

unit of an electrical vehicle system, so

you have majority you can bring

everything into these three categories.

One is thermal management. Another one

is torque management and another one is

energy management. Right? So in a

thermal management you control you

control the temperature and the heating

and its cooling technologies and you

also take care of the optimization of

available continuous and peak power by

thermal optimization. You just control

it like how much amount of peak power

and continuous power you have to provide

and this by doing this you can increase

the range by waste heat energy recovery

system. So these are the things that you

do through a thermal management system

by means of torque management system

what you are what you what on all you

have to do is that you have to calculate

you have to calculate the acceleration

and co down and regenerative braking

torque with respect to this inverter.

Okay. So you also do the regeneration

work also in this torque management

system only and you will be constantly

monitoring the voltage and current

limits of the battery. Right? This also

take care of the functional safety of

the entire system. So finally the energy

management system here you do energy

optimization between the transaction uh

sorry traction and its auxiliary system

that is motor and its another system

that is battery. Now you can also

control the minimum and maximum SOC

condition of the battery. So these are

the three major management system. This

management system actually communicate

with the inverter. Right? This inverter

this is nothing but your power drawing

devices. So this management will be

taken care by means of control of this

inverter. Okay. So how you will control

this inverter? That is done by means of

the processes. Okay. These processes

actually take the input from the sensors

which required to take these inputs and

it will actually process it right. So

what are the inputs? Generally you have

to take these and moreover these

management system interact with each

other. Okay. Because each and everything

will contribute to the other. So if I

want to do let us take a small example

if you are doing a thermal management

system you have to take the torque

management system as an input and

accordingly you have to reduce its

losses. So that will actually uh end up

in the energy management system. So even

these management system interact with

each other and they serve one for the

other right. So what and all they take

the input they take actually the drive

cycle ambient temperature and uphill

downhill vehicle performance calibration

and route planning. So these are the

inputs taken. So these are the inputs

which is being given as a data set to

the control management system and it

also takes the uh input from the

inverter as well. Sometimes we have to

take set some references values also. So

using these values something has to

calculate and it has to manage to the uh

electrical vehicle system so that it is

running perfectly right. So what system

will do that? That system is that

embedded system. That embedded system

will take all the references value

whichever you are giving and whatever

input you are giving and in what

whatever way it has to operated these

points are taken into consideration and

the input which is being given to is is

given as the varying input which is

taken by the uh data set values also. So

using these things the processor will

process by itself and it will manage

these management techniques and for what

purpose to run this vehicle system as a

sustainable vehicle system. So this is

the importance of the embedded system in

an electrical vehicle control system.

Right? So keeping these points in the

mind. Okay. Now we have planned these

sessions in this module. So first thing

basics. So though though you are maybe

you are from different types of uh

domain. So we have certain requirements

for basic level of understanding to go

for the sessions. So first module will

be our basics of electrical. Right? In

this basics of electrical you study

about the circuit current flow and you

know how to measure it and how to check

the faults in the line. So these things

will be taken care in the model one. And

second model is basics of electronics

because electronics is the main key

point for your embedded system. Right?

So whatever electronic components is

available those components what they

actually serve when it is connected in

with this way and what actually how it

actually performs. What is the principle

of mode of operation of this uh

electronic components when they

connected in series when they connected

in parallel? How do they react? These

things will be studied in the basics of electronics.

electronics.

Next, power electronics. So, using this

uh small electronic components, we build

in a circuit and that circuit will

actually convert one form of energy to

the other form at higher voltage level.

So, this will be taken in the power

electronics module.

Next, motor and its drive circuit. So

finally the motor that is the primary

heart of your electrical vehicle system.

This actually gives the power to the

wheel and if you want to define a

vehicle system that is by a means of

specification that is directly the

specification of the motor. So that is

the importance of motor. Is that clear?

So and the drive circuits which actually

drives the motor right and battery pack

and BMS. BMS is also is having a small

sort of embedded system in it because

everything is connected. Okay, first

thing is how do you measure and root

canal the circuit. Second one is what

are the components I have to connect it?

By connecting it what sort of circuit I

will be framing. After framing the

circuit how I will control my vehicle.

Okay. And finally my energy storage

system based upon the requirement of

motor how much power I have to draw from

the battery. Okay. And finally the

embedded system which is connecting all

these things right. How you take the

input from each component and how it is

being made at a made as a control system

vehicle system that will be take seen in

your embedded system and finally we will

try to showcase a prototype which has

been done using these techniques. We

will be small uh developing a small

electric vehicle that you can uh see

through your slides or any video demo I

can show you and that will be shown you

as a small electrical vehicle system

right. Yeah. So this is what we are

going to see in a model. If you have any

doubt as of now with my face or with uh

my uh anything so you can just comment

in the comment box. I'm just giving you

some 1 minute of time to comment you in

>> So my name is Karun Sati. Thank you for

So is the speed okay

or I have to go some more uh in a little

speed. Uh I have to reduce my speed of lecture.

lecture.

Yeah, I will be sharing you the PPT. No issues.

issues.

I'll try through the sharing the P.

Yeah, no issues. Once the session is

So I think uh few of you are uh asking

me to reduce the speed. Yeah,

few are actually satisfied with the

explanation. But anyhow I will take all

your uh points into consideration and uh

since I am planning a session in a

uh I have to give more uh content to you

I'm just uh going in a flow but I

consider that uh

I will uh I think I will be doing it. So

I'll just uh consider all your points

now. I think I can uh take up the

session. Yes. So I am seeing like uh one

or two comments only like I have to

reduce the speed but I'll take this into

consideration. I'm just uh moving moving

So first thing electrical essentials

that is in this session we are going to

see about like electric quantities

electric circuit symbols electric loss

electric circuit series and parallel

circuit AC and DC and power in AC

circuit. So I'm just going in now first

thing wtage. So what is an voltage?

Voltage is the potential difference

between two places. Right? So voltage is

always in a circuit. It is always

measured across two points or you can

say you can connect it in a parallel. So

if you measure the voltage at one point

you will not able to measure it. Right?

So if you see in an input if you are

able to give a voltage say for example

you are voltage as two different uh way

one is AC or it can be a DC voltage

right. So you can use a voltmeter or any

multimeter to measure the voltage. So

here I have showcased a multimeter. So

you have a common point and you have a

voltage point through the voltage

between the wherever you want to measure

the voltage. Your resistor is actually a

load here. This is a resistor, right? So

if you measure the voltage across this

resistor, it will actually showcase in

the digital screen like how much wtage

is there. So probably you'll be knowing

these things. So the only thing you have

to note down is if you're going to

measure an AC voltage make sure you have

kept the knob at the AC and if you're

going to measure the DC voltage it has

to be in DC. So if you want to measure

an AC it will be like sinosidal symbol

over the V over here and in a DC voltage

it will showcase a straight line here.

Next is current. So what is a current?

Current always flows in a line. It is

not measured in a two points. It is

measured always in a series. For each

line there is a current. So current will

always travel in a line. Right? So you

have to connect it in between the line.

So for example you can use almeter or

your multimeter to measure the current.

Here you see this is a circuit. So I am

just cutting the circuit line and I am

connecting it a multimeter across it. So

it has to be connected within the line.

You have to connect the cut the line and

you have to place the multimeter in

between it to measure the current. You

cannot measure the current in between

two points like as you measured in a

voltmeter. So the unit of current is

amp. So similarly here also you have AC

current as well as DC current. So if you

want to measure the AC current you have

to keep your knob at the AC and if you

want to measure DC current you have to

measure in the DC DC knob. Right?

So the current always flows from

positive to negative. In an AC it flows

from phase to neutral. In a general term

the current is always flowing from

higher potential to lower potential. In

a DC the potential is positive. In an AC

the air potential is phase. So you have

to measure the current from higher

potential to lower potential. So the

current has direction. So you have to

keep always in a point like your

positive is connected to the positive

and negative terminal of the myometer is

connected to negative. If you

interchange this knob your uh indication

of the value will be in negative. So the

connect here if you see a negative

symbol that indicates that you are

measuring the current in the opposite

direction the current is flowing in

another way. So you have to understand

in that way right and power. So the

power is nothing but the product of your

voltage and current. The unit of power

is watt. You can use watt meter to

measure the current. So here you can see

the power quality analyzer. So I'm I'm

not recommending any make over here.

This is just image downloaded from

internet. So here you can see using this

clamp meter you can just measure your

current and this this voltage prop will

measure your voltage. All right. So you

have to keep the coil inside this clamp

so that you can measure the current. So

this power will actually uh this power

quality analyzer will actually take the

input from voltage and current. It will

the product of the value will be seen as

a power here. Right? So you can measure

the power also. Power can be written as

I square also by means of losses. Right?

Where I is the current and R is the

resistor. Right?

Next energy. So it is actually the total

amount of work done in a unit time. So

you have energy meters also. This will

be available in your uh online also. You

can just in 2,000 3,000 rupees also. So

you can just measure

uh how much amount of power. This this

doesn't require any time. So this is the

difference between the energy and the

power. Okay. You can measure uh power

also or you can measure in energy also.

Okay. So this power utilizes time for

the it actually utilizes the time also

whereas energy doesn't utilize the time.

So this is the basic difference between

a power and the energy right.

So coming to the symbols right

here you have switches right

in a if you are seeing any circuit right

in that circuit you find find this type

of line diagram only and this type of

symbols only. So here generally this is

called a switch and if it is not

connected with the line it is called as

open switch whereas if it is connected

with the line it is called as close

switch. This is a fuse. So if you buy if

you are working any any uh circuit

drawings or anything else the entire uh

connections of the electrical and

electronic components will be shown as a

single line diagram only. In that single

line diagram they will be using this

sort of symbols only. So you have a

battery and you have cell and you have

voltmeter. So if you have V it is

voltmeter. If A is written it is ameter.

You have buses to show you. Instead of

bushes you may have LED also to display

light. So if the system is connected or

if there is any fault we use generally

an LED or a buser to indicate it. Right?

So that will be like this. So then you

have a resistor. The resistors can be

like load also or it will be in a symbol

also. This is the exact symbol of

resistor. Whereas this is demonstrated

as uh load. Yeah. So when you are

showing is a load they'll be using these

two symbols for your resistors also. So

these are the basic uh circuit symbol

used in any circuit uh of an electrical

system. Right. Now coming to electric

laws. So why this

electric laws are there? Okay. So if you

want to understand the system and if you

want to understand the component what

job of the component uh doing which is

connected in the circuit means you have

to understand certain laws how do they

behave and how it can be calculated. If

you if you know certain values and if

you want to

check whether the unknown parameters in

the circuit. So if you want to follow

any circuit you basically want to know

like how it behaves how the component

this voltage and this uh current

actually behaves in the circuit. So that

is very very necessary to understand the

circuit behavior. So first this is ohms

law. So the ohm's law is nothing but V

is equal to IR that is at constant

temperature your voltage is directly

proportional to the product of its

current and its resistor. Right? So what

you understand from the ohm law is that

just take this as an example. This is a

pipeline. If you want to understand the

electrical circuit working the voltage

and current you just compare it with an

water pipeline, right? So that will

actually make you clear like how this

this uh technology technical term is

working. Right? So if this is a pipeline

the amount of water filled from the tap

or any releasing point to the up uphill

so till the uphill. So the total amount

of water found here is the voltage that

is the potential difference from the

between two points that is the starting

point and the ending point. The point

where it is entering and the point where

it is getting to be utilized the load is

getting connected. So the total amount

of energy available here that is called

as the voltage the amount of water

flowing through the pipe and releasing

out. Okay, that is actually the ampere

that is current. Okay, if this pipeline

is very huge then more amount of current

will go. Okay, that means what? You

don't have any restriction over there.

The restriction is not there. So the uh

water can flow easily. That restriction

is called as the resistor.

Okay. So if your resistance value is

increased, the amount of current going

is decreased. So if the resistance is

very low, the amount of current is high.

So the resistance and the current are

indirectly proportional. So here you can

see we are having two cells and the bulb

is being connected to it. The battery

voltage is 3 volt and the total

resistance is 6 ohms. So that means

what? You have a current of 0.5 amp.

This can be calculated uh ultra also.

How it is? So if you are connecting a

lamp of.5 amp that is understood like

you have a resistance of 6 ohms. So as

you are increasing the resistance your

current is getting actually reduced.

Okay. So this why we are actually uh

using these techniques or why we are

learning these techniques means if you

are going to calculate the battery value

battery value of your vehicle system you

have to basically understand the system.

So this bulb is your load. So whenever

you are connecting a load to a circuit

at that time only the current will flow.

So as you are connecting a load you have

to calculate like total amount of

current required. Okay. And you also

need to study like whether this much

amount of voltage if I have in my cell

that much amount of current can be

provided. So this calculation you may

think like it is a small law we can just

memorize the value. No it is not like

that by equation you can find the

unknown parameters. But why that law is

used? How you are going to apply it to

your application that is actually very

very important. So using this Ohm's law

you'll be able to calculate like if this

much amount of load I'm going to connect

to my battery. So how much amount of

voltage I have to withstand in my

battery to give that much amount of

current. So that actually is calculated

using this ohms law. So this is what

this is how you need to understand the

system towards your application. Then

the subject will be easy for you as well

as the equations or nothing can disturb

your uh thing. Right? When this is this

uh comparison between the application

and your studies is bridged then you can

actually understand the system very

easily. Right? Next

laws another laws are electric and

magnetic circuits law that is kit's law.

Okay. You have two laws that is kit's

current law and kit's voltage law. So

what actually this law gives if you

there are certain laws proposed using

those laws what you can do is that you

can find some unknown parameters. This

will be helpful like how much amount of

current is going to one particular load

without measuring without able measuring

that point you can actually calculate

like how much amount of current in the

paper itself. So this sort of loss will

be actually helping you in this aspect

right see this is actually a circuit

okay this circuit in this circuit in an

embedded system if you see a motherboard

you'll be seeing like you can you only

the resistors either by means of a LED

or or directly by connecting a resistors

you'll see a number of resistors these

resistors serve as the load load means

what in a circuit this if these

resistors are connected at based upon

these resistors the current will flow.

So this is the logic. So if you find any

motherboard or any any sort of embedded

system board you'll be seeing any number

of resistors in a circuit and LEDs. LEDs

also actually a resistor. So what are

resistor is means whichever load which

is emitting light or heat. Okay that is

actually a resistive load. Either you

can connect a resistor or you can

connect any resistive load to handle the

current to limit the current. So here in

this circuit if if this is a circuit and

these are the resistors connected in the

circuit. See R1, R2, R3, R4, R5, R six,

R7 and R8. So certain resistors are

connected in series. Certain resistors

are connected in par. So in a circuit

what you have to understand is you know

the symbols through the symbols you will

identify this is a battery and these are

resistors and they serve as a load for

the system right here you can see there

are loops. So what is a loop? Okay these

are nodes and this is called as

branches. Okay node is a point where n

number of resistors are connected to

single point that is called as load.

Okay. And the resistors which is

connected in parallel okay between two

uh point of the battery that is actually

the branches. Here you have two branches

R2 and R3 right any network which is

closed they form a loop. So you here you

have three loops 1 2 and three. So this

is the basic uh components of a circuit

right. What actually the kchov's law

say? current law first current law what

current law says is that towards a node

in this is a node the current will

actually enter you know that how the

current will flow right before that I'll

just tell how the current will flow as I

said earlier the current will flow from

higher potential to lower potential that

is positive to negative so this is the

positive and this is the negative my

current is going to flow through here

this resistor R1 will take some

resistance and the remaining amount of

current travels to this node When it

reaches this node, the current will

actually divide to this branch and this

branch that is to R2 and R3. Similarly,

after reaching R3, it will reach at the

current at this node. Right? This node

from this node again the current will

move to R4 and R5. So again it will go

to this point and it will reach the load

and it will come to this resistor and it

will reach the negative point. So this

is how the current will actually travel.

The current will actually travel in the

minimum resistance path. Okay. So the

current will travel from positive to

negative through minimum resistance

path. So wherever there is a node, the

current will reach the node and divide

to different branches. Right? This is

how the current will travel in a

circuit. So what Kirchov's current law

states is that the sum of the current

entering towards the node and the sum of

will and the sum of the current leaving

away from the node will be equal to

zero. Here in this circuit you can see

right the current entering to the node

is I1 I2 and I3. The summation of that

current plus the summation of current

which is leaving that is I4 and I5 that

is minus right. When it is leaving it

will denote in the minus. So if you take

the summation of all the current, you'll

be getting the zero. This is the

Kirchoff's current law. Similarly, what

is Kirchoff's voltage law? In a closed

loop, this is the closed loop, right? In

a closed loop, the summation of voltage

across all the terminals will be equal

to zero. So what are the voltage

terminals available here? You see a A

and D, wtage across AB, wtage across BC,

voltage across CD. So if you sum all

this voltage that will be equal to zero.

So using these two laws and the ohms law

you will be able to identify the

behavior of any circuit as well as you

can also find the parameters of unknown

values. So this is the usage of these

two laws. See

if these two laws as well as the Ohm's

law is being into your mind and if you

are able to identify like how the

current is flowing towards the circuit

any embedded system can be solved by

you. You can just trace any system and

by by means of any uh calculation you

can find the unknown parameter also. And

also if particular resistor is not

working that also you can identify like

because if this resistor is there this

much amount of current only will be

traveling away from that resistor. Okay.

Here you know how much amount of current

is flowing. You know the voltage you

know that you are measuring the current

here and you are measuring the current

here. You know the resistor value. So by

using Ohm's law if you are able to find

like the current value at this point and

it is not matching with the value which

you are measuring through the multimeter

what you can understand is that this

resistor is not working. So this also

for these things only these laws are

there and you can also you can uh

utilize all sort of uh equations to find

sorry these laws to find the unknown

parameters right. So this is the benefit

of studying these laws. Next electric

circuit. So if you see an electric

circuit you have different types of

electric circuit. One is closed circuit,

another one is open circuit, another one

is short circuit and another one is

series and parallel. Right? So what is a

closed circuit? There is a energy source

that is battery that is being connected

to the load positive to positive and

negative to negative. When you connect

the load, the current will travel.

Unless and until you connect this bulb,

you'll have only the voltage across this

battery. You cannot find any current. As

soon as you connect your bulb, the

current will start to flow from positive

to negative through the load. If this is

happening fine, then it is called as a

closed circuit. Right? What is a open

circuit? The positive terminal of the

thing is connected to the positive

terminal of the load and negative

terminal is connected to the negative

terminal of the load. If you are

disconnecting any one wire, then that is

called as a voltage circuit. Okay. So,

so sorry open circuit. So when the

circuit is open then also the voltage

will flow from this point and this point

across these two points the voltage of

the battery will be showing. Okay.

Though the light is not going because

the current is not if the circuit is

closed only the current will flow. Since

the circuit is open the current will not

flow the but if you measure the voltage

using the voltmeter across this positive

and negative in this wire you can see

the amount of voltage present inside the

battery. So though the circuit is open

the voltage will flow but since the

circuit is open the current will not

flow. So next coming to the short

circuit. What is the short circuit? If

you through a wire if you are connecting

the positive and negative terminal of

the battery then the circuit is called

as the short circuit. So when the

circuit is shorted your current will be

maximum your voltage will be zero. This

is the main important point you should

always keep in your mind because in a

embedded system or in a power electronic

circuit all all the components are

connected from one point to the other

and they make a closed circuit. If the

circuit is not closed the flow of

current will not happen. So if you see

the flow of current as zero and the

voltage is there then you have to come

to a conclusion like your circuit is

open and it is not closed it is not

connected. If the circuit are connected

but then also your uh application is not

working but the meter is reading a high

amount of current then what you have to

understand is that some problem is there

within the component because of that the

circuit is getting uh shorted and

because of that my meter is reading high

current but not voltage. So like this

only you have to trace the circuit and

identify what is the range of voltage

and what is the range of current. From

that range of voltage and current, what

is the problem in the circuit? So, this

is the use of studying the circuit and

its branches. Right? Next comes the

series and parallel. This is based upon

the load connected to the load

connecting to the circuit. If your load

is connected from positive to the

positive terminal of your load and the

negative is connected to the next

positive terminal of another load and

the negative of this load is connected

to the negative of this load and this

node is connected to the negative of

this load. If you connected it this way,

this is called a series circuit. Okay.

Here the current is flowing to first

bulb and then the second bulb and then

the third bulb and it is ending to the

negative. Similarly, your voltage also

travels from higher potential to lower

potential across all the loads and then

it reaches the negative point. Whereas

if you take a parallel circuit, if you

have n number of loads, all loads will

have same positive and same negative

from the battery then that is called as

parallel circuits. The loads are

connected in parallel. So what happens

when you connect all the loads in series

and what happens when all the current

loads are connected in par. So that we

are going to see now. So this is a

series circuit right. So in this series

circuit here you can see the current is

flowing from your positive and reaching

the positive of this first load and then

the negative of this load is connected

to the positive of this load and finally

the negative of this load is connected

to the battery. So the current is

traveling through here reaching the

first resistor and reaching the second

resistor and finally the negative. Okay.

Whereas in parallel if you see the bulbs

are connected here the current is

traveling through this from the positive

it is reaching this node right this node

from this node it is going to first bulb

and it is divided to the second bulb and

again the current is coming out from

each uh load and it is combining in this

node node two and it is reaching the

negative. So this is the difference

between the series and parallel. Okay.

So now here we are going to see the

difference between the series and

parallel connection. The first point is

in the series the same amount of current

flows through all the components in a

series. Whereas here if you see the

current flowing through each component

combines to form the current flow

through the source. That is the

summation. Right? Here the current is

divided and then again it is getting

added. Right? Here in an electric

circuit components are arranged in a

line in a series. Whereas here in this

electric circuit components are arranged

parall to each other. Okay. So coming to

the technical point third that is when

resistors are put in a series circuit

the voltage across each resistor is

different. Even though the current is

flowing through them are same the

voltage drop will be there in each

resistor. That is here. If you see the

current is same to this component as

well as this component. But if you

measure the voltage across this terminal

and this terminal there will be a

voltage drop. And similarly if you

measure the voltage across this terminal

and this terminal there will be a

voltage drop. So you have a voltage drop

in the series circuit and current is

same whereas in the parall circuit you

have difference in current and voltage

is same. Right? So this is the primary

difference between a series and parallel

circuit. Right? Here you can see in

series if one component is break down

then the circuit will become a open

circuit. So the current flow of current

will not be there. Whereas in parallel

if one component is break down then also

the circuit is actually a closed

circuit. So the current will flow to the

rest of the components. So when you

connect everything in a series you can

save more amount of

uh same amount of current will be there

whereas in the case of parallel you draw

more amount of current but the voltage

will be same. So if you want to store

the energy you have to store it in by

means of connecting in series you can

store the usage of current whereas if

you connect in parallel the usage of

current will be more so that your

battery will drain faster. So this is

the practical difference between a

series and parallel connections. Right?

Now coming to technical explanation

about this. So here if you see in a

current divider. So if you are

connecting your resistors parallelly

that is load one and load two parallelly

with respect to this voltage. Now what

happens the current is coming the

current is getting divided in branch one

as I1 and then the remaining amount of

current is sent to this branch. And if

you see at this node you can see the

current is getting divided into I R2.

And finally when they reach at the

negative all the current is getting

summed up at this node and it will reach

at the current. So the entering current

it will be equal to the living current

it. Okay. But the current value varies

based upon the different loads. Whereas

if you see the voltage uh sorry in uh

here if you see the voltage the voltage

will be same at these two terminal also

the the same voltage will be across

these two terminals also and the same

voltage will be across these two

terminals. Coming to series connection

right coming to the series connection

your resistance is connected series

here. Here if you see the current

entering to this is I the same amount of

current will be leaving here though the

current is not getting dropped any here.

Whereas if you see the voltage the

voltage across these two terminal based

upon if you measure the voltage across

these terminal two terminal that will

give the entire voltage but if you

measure the voltage across this R1 and

this R2 you'll be getting different

types of voltage drops they are called

as the voltage drops. So when you

connect the series uh loads your voltage

is getting divided. When you connect the

parall load your current is getting

divided. So this is the difference

between a voltage divider and this is

what happens when you connect a load in

series and in a parallel. So why this is

actually very much important in an

electrical vehicle system is the energy

system which you are using in electrical

vehicle is battery. that battery

actually decides the range of the

vehicle. That is the practical

application. If you see the practical

application, I am really worried about

when I'm taking it as a vehicle, I'm

actually really worried about the range

of my vehicle. So I I want to charge my

battery and I have to drive it to a huge

distance. I want to travel a huge

distance. Now I need a more range. But I

have to keep my battery as the only

source for giving the supply to the all

electrical and electronic components

which is there in the electrical

vehicle. So that also consumes the

energy from the same battery. So how I

can improve my range is that by

intelligently calculating the loads

connecting it in series and parallel

still I can save my voltage and current

right. So I am I am actually really

worried about like how much amount of

current I'm drawing. Right? So by

intelligently planning all the

components connecting how I am

connecting it either in a series or

parall with respect to the battery I can

actually manage the energy management

system. So if my energy is managed what

I can ultimately achieve is that I can

ultimately achieve my range of coverage

that means what I am increasing the

overall performance of my vehicle

system. So though you are studying about

the circuit and these things ultimately

what you are going to reach is that you

are actually improving the vehicle

systems performance. Okay. So to

increase the vehicle system performance

you need to understand the engineering

behind it. Basic first basic level of

engineering. Once this basic level of

engineering is understood, then you can

build in a circuit in such a way like

though the amount of current is drawn,

this will be uh actually managing your

uh energy management very perfectly. So

first thing what you want to not is you

need to know the scratches of this

engineering principle. Right? So this is

what we are going we are going in a flow

now. So coming to next AC and DC, right?

So there are uh so I'm just giving

another uh one minute break over here to

check out the comment boxes. So

if you have any doubt till now you can

just uh leave it in your live chat. I'm

just seeing your live chats. I can just

uh clarify your dudes and we can proceed

with that. Yeah I'm just giving a break

of one or two minutes. Right.

And now whether my speed is okay or not

that also you just give us a comment so

Yeah. Okay. I think now I am okay with

my speed. I'm getting more uh

positive responses towards the speed.

Yes. Fine. Thank you. Okay. Just I'm uh

So now as of now we were actually uh

checking with uh different types of

components and circuits right now I am

actually worried about my load. Okay. So

what is my load? When I connect my load

my then only my voltages and current

then only my current is going to flow

through my circuit and that load is only

going to make my circuit as a clos

circuit. Right? And that load is only my

application based uh thing within the

circuit. Other things are not

application based. My uh load is what if

I'm using a fan that is a load and that

is actually my that I'm actually

deriving the benefit from my fan only

because if I know need air I'm just

switching on my fan if I want to read

any document I'm just switching on my

light so that is my application that

application is technically the load for

my circuit right so that load in an

electrical vehicle system can be of two

types that is it can be a AC load or it

can be a DC load though it is a AC load

or a DC load. I am having my energy

source as a DC only that is my battery

only. Right? So basically I need to

understand the difference between my AC

and DC so that I can uh I can actually

change my DC energy to AC energy or AC

form of energy to DC energy uh DC form

of energy according to my requirement.

So for that I need to know basically

what is the difference between the AC

and DC right. So as you all know AC is

defined as alternating current and DC is

defined as direct current right. So

the AC type of load are generally

resistive, inductive and capacitive and

uh DC loads are only resistive. Okay.

And the main point here is uh that in an

AC the current which I was telling right

when you connect a load the current will

flow right in an AC as this current is

alternating as the name is uh denoting

the current will actually have travel in

both the direction. Okay from phase to

neutral as well as neutral to phase

according to the change of uh cycle.

Whereas in DC you the current will flow

in only one direction that is positive

to negative right whereas uh because of

that you found you find a component

called frequency. So the frequency you

have in a AC signal whereas you don't

have a frequency in a DC signal. Okay.

So here if you see uh

power factor I'm coming to the next

actually the power factor. So the power

factor is uh lies between 0 to one

whereas in DC it actually uh

remains one alone. So these are actually

the basic difference between an AC and

DC. The only fundamental thing what you

want to know is that when you connect a

AC load the current direction will be in

both way phase to neutral and neutral to

face in an alternating way. Whereas in

DC it is from positive to negative only.

In AC you have frequency whereas in DC

So in an AC circuit you have three

components that is the real power,

reactive power and apparent power and

you have power factor. So what is

actually an active power? Active power

is the true power. So in a transmission

line you'll be this actually why I have

put here is in an electrical vehicle

system you are going to connect an

electrical vehicle system to a EV only

right that EV can that grid can provide

only your AC supply. So when you connect

a vehicle it is very much necessary like

which form of energy you are going to

receive through the charger and you are

connect converting it to a DC and you're

going to give it to a battery pack right

so this is actually very this study is

actually very very important why because

the power which you are going to draw

from the grid it should be of real power

if it is reactive power in a meter it

will show reading but you will not be

you will not be using that power. So

what is a reactive power is actually the

power which is not being used that is

actually the reactive power. Okay. So

you can uh apparent power is the

algebraic sum of this uh active power

and uh reactive power. So these are

actually the powers. So what the the key

point is the power which you are drawing

drawing from the grid. So if you want to

get some power from the grid, you need

to give some power from your load. So my

load is my electrical vehicle. I am

connecting the battery with my grid and

grid to my battery. So if I want to get

supply from the uh grid, I need to feed

some reactive power from my battery. If

I give some amount of reactive power to

the battery, then only I will get some

more amount of active power map from my

grid. So what I will do is that say for

example I want to get 100% from my EB.

Now what I am going to give is I will

just give some 10% to 50% as reactive

power to the grid. Then only it will

give the remaining 90% from my uh grid

that is the real power. So I need to use

the real power to the from the grid and

I have to make sure that the power which

is coming from the transmission is a

real power. That is actually very very

I am having a question here for

transmission DC is better only above

break even distance around 500 for

shorter distance AC. Yeah. Okay. So he

has given an additional point. So you

may just go through it right. So I

thought it was a doubt uh but it is uh

key point you can just note it around.

I'm just continuing with my session here.

here.

So these are when you connect an

inductive load or a capacitive load. So

what is an inductive load? Whichever

load which is rotating in an electrical

vehicle system your motor is an

inductive load. Right? Whereas your uh capacitive load means battery battery is

capacitive load means battery battery is a capacitive load. So if you connect a

a capacitive load. So if you connect a capacitive load your power factor will

capacitive load your power factor will be actually leading like this. So if

be actually leading like this. So if this is your active power and this is

this is your active power and this is your act this is a power triangle. So

your act this is a power triangle. So this is an apparent power. So if you

this is an apparent power. So if you connect a capacitive load actually the

connect a capacitive load actually the your power factor will be leading the

your power factor will be leading the active power. Whereas if you connect an

active power. Whereas if you connect an inductive load that is motor or these

inductive load that is motor or these things your power factor will be lagging

things your power factor will be lagging the active power. So generally we have

the active power. So generally we have for a good power flow you'll be

for a good power flow you'll be maintaining a power factor as one. So if

maintaining a power factor as one. So if power factor is one your uh actually if

power factor is one your uh actually if you take the power uh power equation

you take the power uh power equation previously which I have shown power

previously which I have shown power equation is nothing but wtage into

equation is nothing but wtage into current correct but actually power is

current correct but actually power is voltage into current and power factor

voltage into current and power factor cos theta. Okay, this this is the cos

cos theta. Okay, this this is the cos theta. So generally we will take for an

theta. So generally we will take for an ideal situation power factor to be one.

ideal situation power factor to be one. If the power factor is one, your product

If the power factor is one, your product of voltage and current is actually equal

of voltage and current is actually equal to the power. But in a real scenario, we

to the power. But in a real scenario, we don't have power factor as unity. So in

don't have power factor as unity. So in our Indian scenario, the power factor is

our Indian scenario, the power factor is actually 0.9. So wtage into current into

actually 0.9. So wtage into current into 0.9 will give you the actual power. So

0.9 will give you the actual power. So that is your active power that is

that is your active power that is measured in watts. Okay. So here if you

measured in watts. Okay. So here if you see this theta is leading or lagging

see this theta is leading or lagging that is based upon the load which you

that is based upon the load which you are connecting. So the inductive loads

are connecting. So the inductive loads will give a lagging power factor and uh

will give a lagging power factor and uh capacitive load will give you a leading

capacitive load will give you a leading power factor. The capacitive load in an

power factor. The capacitive load in an electrical vehicle system is a battery

electrical vehicle system is a battery whereas inductive load is rotating

whereas inductive load is rotating component that is motor. So whichever

component that is motor. So whichever load is rotating that is actually the

load is rotating that is actually the inductive load. As already I told

inductive load. As already I told whichever load which is giving heat or

whichever load which is giving heat or light as an output that can be

light as an output that can be considered as the resistive load.

considered as the resistive load. Whichever uh load can store the energy

Whichever uh load can store the energy okay that can be considered as your

okay that can be considered as your capacitive load. Right? So this is

capacitive load. Right? So this is actually the uh different types of load

actually the uh different types of load and this is the impact towards the EB

and this is the impact towards the EB which is being connected. Right? Next

which is being connected. Right? Next with this I'm just concluding my

with this I'm just concluding my electrical essentials. So now we are

electrical essentials. So now we are going in for electronic essentials. So I

going in for electronic essentials. So I think with this uh electronic essential

think with this uh electronic essential we will close this session. I'll try to

we will close this session. I'll try to wrap up before 12. Uh yeah. So coming to

wrap up before 12. Uh yeah. So coming to electronic essential in this electronic

electronic essential in this electronic essential what you're going to see is

essential what you're going to see is that electronic components and

that electronic components and essentials around electronic components

essentials around electronic components and different types of electronic

and different types of electronic switches. So if you take any circuit, if

switches. So if you take any circuit, if you find any motherboard, you have only

you find any motherboard, you have only these components that is electronic

these components that is electronic components and switches. So other than

components and switches. So other than that you cannot find any anything else.

that you cannot find any anything else. These electronic components are

These electronic components are connected in such a way that they make a

connected in such a way that they make a circuit. So when they make they when

circuit. So when they make they when they are formed into a in a form of a

they are formed into a in a form of a circuit, they actually serve the

circuit, they actually serve the performance either to convert one form

performance either to convert one form of energy to the other form or one form

of energy to the other form or one form of signal into the other signal. So this

of signal into the other signal. So this is the basic uh thing about an

is the basic uh thing about an electronic circuit. So coming to first

electronic circuit. So coming to first point that is electronic components.

point that is electronic components. So the basic electronic components

So the basic electronic components available in this uh system is that not

available in this uh system is that not in the system but in entire uh thing uh

in the system but in entire uh thing uh wherever you see any electronic devices

wherever you see any electronic devices you can find only these electronic

you can find only these electronic components that is capacitors, resistors

components that is capacitors, resistors and inductors. First points and apart

and inductors. First points and apart from that you find switches. One is two

from that you find switches. One is two terminal switch diode and another one is

terminal switch diode and another one is three terminal di switch that is

three terminal di switch that is transistors and finally you find some

transistors and finally you find some IC's in this IC's everything is

IC's in this IC's everything is programmed or any electronic circuit is

programmed or any electronic circuit is programmed within this IC's these are

programmed within this IC's these are called as microchips right so these are

called as microchips right so these are the different types of components

the different types of components available in different modes I have just

available in different modes I have just showcased over here so basically you

showcased over here so basically you have capacitors resistors and inductors

have capacitors resistors and inductors apart from that you have switches one is

apart from that you have switches one is controlled switch that is

controlled switch that is transistors that is three terminal and

transistors that is three terminal and another one is uncontrolled switch that

another one is uncontrolled switch that is diode right so diodes are two

is diode right so diodes are two terminal and you you can find some

terminal and you you can find some microchips that will perform any

microchips that will perform any electronic circuit or any logical

electronic circuit or any logical operations right

operations right first thing resistors so what resistors

first thing resistors so what resistors are it offers electrical resistance to

are it offers electrical resistance to the flow of current I think you are

the flow of current I think you are studying ohm's law also I have told the

studying ohm's law also I have told the same

same So it actually limits the current and it

So it actually limits the current and it is measured in ohms. Higher the

is measured in ohms. Higher the resistance, lower the current flow.

resistance, lower the current flow. Lower the resistance, higher the current

Lower the resistance, higher the current flow. Okay. The resistance can be as I

flow. Okay. The resistance can be as I say said they serve as the load. It can

say said they serve as the load. It can be connected either in series or

be connected either in series or parallel. So when you connect a resistor

parallel. So when you connect a resistor in series was what happens and when you

in series was what happens and when you connected in parallel what happens. So

connected in parallel what happens. So these are the these are the things we

these are the these are the things we have seen already. So this is actually

have seen already. So this is actually the form of uh resistors. You have color

the form of uh resistors. You have color codes. So using this color codes you can

codes. So using this color codes you can find the value of this resistor how much

find the value of this resistor how much ohms it is. So you can just Google the

ohms it is. So you can just Google the color code of resistor. You'll find it.

color code of resistor. You'll find it. So how to calculate the values? These

So how to calculate the values? These are very primary. So I'm just skipping

are very primary. So I'm just skipping it out. So you can just Google and you

it out. So you can just Google and you can just find the images using this

can just find the images using this color code. You'll be finding the value

color code. You'll be finding the value of the resistor. So if you are not a you

of the resistor. So if you are not a you if you are not able to have you are not

if you are not able to have you are not having any time to find the color code

having any time to find the color code learnings you just take the multimeter

learnings you just take the multimeter connect across these two things and

connect across these two things and you'll uh the multimeter will indicate

you'll uh the multimeter will indicate how much amount of ohm is there in the

how much amount of ohm is there in the resistor right so what are the unique

resistor right so what are the unique functions of this resistor it actually

functions of this resistor it actually adjustes the current flow to the control

adjustes the current flow to the control circuit next it actually pro serves as a

circuit next it actually pro serves as a protective component okay so what you

protective component okay so what you can do is that if you want to protect

can do is that if you want to protect any load. Okay. What you can do is that

any load. Okay. What you can do is that say for example that particular load say

say for example that particular load say for example you are connecting a lamp

for example you are connecting a lamp that lamp is of actually a 3 ampere.

that lamp is of actually a 3 ampere. Okay. So now what you can do is that

Okay. So now what you can do is that because of any short circuit in the

because of any short circuit in the circuit or because of any malfunction in

circuit or because of any malfunction in any circuit there is a chance like that

any circuit there is a chance like that particular lamp can receive more than 3

particular lamp can receive more than 3 amps. So for that what you can do is

amps. So for that what you can do is that you can just add a resistor in

that you can just add a resistor in before the lamp so that that resistor

before the lamp so that that resistor will block the maximum current and it

will block the maximum current and it will allow only a 5 ampere of current to

will allow only a 5 ampere of current to the lamp. So like this also you can just

the lamp. So like this also you can just this

this resistors will serve as a protective

resistors will serve as a protective devices also. It can also create a

devices also. It can also create a voltage drop. Okay. So if you are just

voltage drop. Okay. So if you are just connecting it in a series then it will

connecting it in a series then it will create a voltage drop. when you are

create a voltage drop. when you are connecting it in ser

parallel it will create a current drop. So like this you can just use the

So like this you can just use the resistor in multiple way right. So these

resistor in multiple way right. So these are the unique functions of this

are the unique functions of this resistors. Next capacitors as you all

resistors. Next capacitors as you all know capacitors are actually a

know capacitors are actually a construction wise if you see it is a two

construction wise if you see it is a two plate. It is the different uh it is

plate. It is the different uh it is separated by means of a dialectric

separated by means of a dialectric component. So if you connect a positive

component. So if you connect a positive terminal to one plate the other terminal

terminal to one plate the other terminal will actually turn it as a negative by

will actually turn it as a negative by itself. So capacitor is not having any

itself. So capacitor is not having any positive terminal or negative terminal.

positive terminal or negative terminal. As you connect it any terminal to the

As you connect it any terminal to the positive it actually makes itself as a

positive it actually makes itself as a positive terminal and the other terminal

positive terminal and the other terminal will the remaining left terminal will

will the remaining left terminal will become as a negative terminal. So it is

become as a negative terminal. So it is available in different forms like

available in different forms like ceramics and it is available in film,

ceramics and it is available in film, mica etc. So it is actually measured in

mica etc. So it is actually measured in far. Okay. So capacitors can be

far. Okay. So capacitors can be connected in series or parall to

connected in series or parall to decrease or increase the overall

decrease or increase the overall capacitance of a circuit. So actually

capacitance of a circuit. So actually what these capacitors will do is that if

what these capacitors will do is that if you connect a capacitors in a circuit,

you connect a capacitors in a circuit, it actually stores the voltage and it

it actually stores the voltage and it will again discharge the voltage

will again discharge the voltage available voltage. So what I can do is

available voltage. So what I can do is that

that if you connect a capacitor it will store

if you connect a capacitor it will store the energy in the form of voltage and if

the energy in the form of voltage and if there is sudden drop in voltage if I'm

there is sudden drop in voltage if I'm connecting if I'm giving a voltage input

connecting if I'm giving a voltage input to a load and if I'm having a capacitor

to a load and if I'm having a capacitor in between the voltage and the load now

in between the voltage and the load now what happens is that if there is a drop

what happens is that if there is a drop in input wtage this capacitor will try

in input wtage this capacitor will try to give the stored wtage to the

to give the stored wtage to the component. So if I give if the since

component. So if I give if the since this voltage is given by the capacitance

this voltage is given by the capacitance what we call it as it will actually

what we call it as it will actually regulate the voltage in the system.

regulate the voltage in the system. Okay. It constantly charges and

Okay. It constantly charges and discharges. If you give input it charge

discharges. If you give input it charge if you stop the input it will start to

if you stop the input it will start to discharge. So while it is discharging it

discharge. So while it is discharging it will discharge to the giving the voltage

will discharge to the giving the voltage to the load. So it actually regulates

to the load. So it actually regulates the voltage. Uh to maintain the equal

the voltage. Uh to maintain the equal voltage towards the circuit we actually

voltage towards the circuit we actually implement this capacitor. It actually

implement this capacitor. It actually stabilizes the voltage. You can keep it

stabilizes the voltage. You can keep it in that way. So in a circuit if you want

in that way. So in a circuit if you want to stabilize it will actually uh give

to stabilize it will actually uh give you in the this capacitance will give a

you in the this capacitance will give a stabilized voltage in the system. Right?

stabilized voltage in the system. Right? So this is actually the real job of a

So this is actually the real job of a capacitor and inductor. So inductor is

capacitor and inductor. So inductor is nothing but so three components. One is

nothing but so three components. One is resistors we have seen and the other one

resistors we have seen and the other one is

is uh capacitance that we have seen and

uh capacitance that we have seen and finally the inductance. So the inductors

finally the inductance. So the inductors are nothing but it is a single coil

are nothing but it is a single coil single wire which is made as a winding

single wire which is made as a winding like this. So if you turn around the

like this. So if you turn around the wire in this way they form as a

wire in this way they form as a inductor. Okay. So it is also actually

inductor. Okay. So it is also actually stores the energies and discharge energy

stores the energies and discharge energy just like the capacitor. Okay. Its unit

just like the capacitor. Okay. Its unit is called as the Henry. Okay. Capacitor

is called as the Henry. Okay. Capacitor stores the energy in the form of a

stores the energy in the form of a electrostatic way whereas inductor

electrostatic way whereas inductor stores the

stores the energy in the form of electromagnetic

energy in the form of electromagnetic way. So because of that what happens is

way. So because of that what happens is that you are charging the capacitor

that you are charging the capacitor connected by connecting it in positive

connected by connecting it in positive and negative and if you're discharging

and negative and if you're discharging it still the discharge current will flow

it still the discharge current will flow in the same direction. Okay. While

in the same direction. Okay. While discharging also the current will flow

discharging also the current will flow from positive to negative only. Whereas

from positive to negative only. Whereas in an inductor you are just storing you

in an inductor you are just storing you are charging it by means of an input.

are charging it by means of an input. Now the inductor is getting charged. Now

Now the inductor is getting charged. Now if you stop the supply the inductor will

if you stop the supply the inductor will discharge right? Now the inductor will

discharge right? Now the inductor will discharge in the opposite polarity. The

discharge in the opposite polarity. The current will discharge in an opposite

current will discharge in an opposite way. So because of that the inductor

way. So because of that the inductor polarity will change. Okay. So if you

polarity will change. Okay. So if you charge the capacitor the char the

charge the capacitor the char the capacitor will charge in positive

capacitor will charge in positive negative and discharge in positive

negative and discharge in positive negative only. Similarly, if you charge

negative only. Similarly, if you charge an inductor, it will charge in positive

an inductor, it will charge in positive negative and while it is discharging,

negative and while it is discharging, the polarity of the inductor will

the polarity of the inductor will change. Now, the current direction also

change. Now, the current direction also will change accordingly. So, this is the

will change accordingly. So, this is the basic difference between the difference

basic difference between the difference between capacitors and inductors. So,

between capacitors and inductors. So, the unique functions of this inductors

the unique functions of this inductors are it blocks the unwanted signal from

are it blocks the unwanted signal from the radio interferences and it makes it

the radio interferences and it makes it actually converts the AC to DC. Okay.

actually converts the AC to DC. Okay. Then when you implement in a circuit

Then when you implement in a circuit you'll understand it. Okay. So it is

you'll understand it. Okay. So it is actually serves as a sensors also at

actually serves as a sensors also at some points. So these are the unique

some points. So these are the unique functions of inductors. Right

now coming to power semiconductor devices that is switches. Okay. This is

devices that is switches. Okay. This is actually the important point. Now as I

actually the important point. Now as I said the electronic the general

said the electronic the general electronic components available here are

electronic components available here are resistors, inductors, capacitors and

resistors, inductors, capacitors and switches. So what are the switches?

switches. So what are the switches? These switches are made up of

These switches are made up of semiconducting materials. They are

semiconducting materials. They are called as semiconductor switches. So

called as semiconductor switches. So these switches are used in all the type

these switches are used in all the type of electronic circuits along with this

of electronic circuits along with this components. So based upon these switches

components. So based upon these switches only the circuit are on and off. Okay.

only the circuit are on and off. Okay. So these are the power semiconducting

So these are the power semiconducting devices. You have two terminal devices

devices. You have two terminal devices and three terminal devices. As I said

and three terminal devices. As I said two terminal devices are called as

two terminal devices are called as diodes and three terminal devices are

diodes and three terminal devices are called as transistors. The diodes are

called as transistors. The diodes are uncontrolled.

uncontrolled. Uncontrolled means you can just turn on

Uncontrolled means you can just turn on the diode but you cannot turn it off.

the diode but you cannot turn it off. Whereas transistors you can turn on and

Whereas transistors you can turn on and turn off whenever it is required. Okay.

turn off whenever it is required. Okay. So these are the differences between the

So these are the differences between the two devices. One switches are called as

two devices. One switches are called as uh diodes and other type of switches are

uh diodes and other type of switches are called as transistors. Diodes are

called as transistors. Diodes are uncontrolled switch. You cannot you turn

uncontrolled switch. You cannot you turn it off. You can just turn it on. You

it off. You can just turn it on. You cannot turn it off. Whereas transistors

cannot turn it off. Whereas transistors you can turn it on and turn it off

you can turn it on and turn it off whenever it is required. So these are

whenever it is required. So these are the functional differences between these

the functional differences between these two switches.

two switches. So basic uh definitions of diode is so

So basic uh definitions of diode is so it is a semiconductor devices. It allows

it is a semiconductor devices. It allows the current in only one direction. It

the current in only one direction. It has anode and cathode. The current will

has anode and cathode. The current will travel from anode to cathode whenever it

travel from anode to cathode whenever it is switch on. Okay. So it it uh when

is switch on. Okay. So it it uh when when these two terminals are connected

when these two terminals are connected to the respective polarities the voltage

to the respective polarities the voltage and current starts to flow and uh if it

and current starts to flow and uh if it is connected in different polarity the

is connected in different polarity the voltage flow will not be there. So this

voltage flow will not be there. So this is how the diode will interact. So the

is how the diode will interact. So the unique features of diodes are still we

unique features of diodes are still we will see about this diode in deeper but

will see about this diode in deeper but the as a basic level of introduction I'm

the as a basic level of introduction I'm just giving you these things. So the

just giving you these things. So the unique features of this diodes are it is

unique features of this diodes are it is used as in rectification to convert AC

used as in rectification to convert AC to DC power. It actually limits the

to DC power. It actually limits the noise through the clipping circuit. It

noise through the clipping circuit. It also performs digital logical operations

also performs digital logical operations like ANDgate or Ngate. Okay. So

like ANDgate or Ngate. Okay. So multiplying voltage in combinations with

multiplying voltage in combinations with capacitors. Protects the devices from

capacitors. Protects the devices from reverse supplies. Limiting large voltage

reverse supplies. Limiting large voltage spikes with inductors. So these are the

spikes with inductors. So these are the unique features of this diodes. So here

unique features of this diodes. So here you can see the diodes available

you can see the diodes available realtime diodes available in different

realtime diodes available in different formats.

formats. Next the transistors. The transistors

Next the transistors. The transistors are three terminal devices.

are three terminal devices. It can be of any fashions. So switching

It can be of any fashions. So switching devices that can also act as an amp.

devices that can also act as an amp. This this can be act as an amplifier as

This this can be act as an amplifier as well as switching operations also in an

well as switching operations also in an electrical vehicle system. If you see we

electrical vehicle system. If you see we are not using transistors as a

are not using transistors as a amplification here. We are just using as

amplification here. We are just using as a switches. Okay. So as I said it it is

a switches. Okay. So as I said it it is available in two types of

available in two types of configurations. One is bipolar junction

configurations. One is bipolar junction transistor that is BJT that is for low

transistor that is BJT that is for low current application and you have field

current application and you have field effect type of transistor that is of low

effect type of transistor that is of low voltage application. So wherever you are

voltage application. So wherever you are having low current you can use bipolar

having low current you can use bipolar junction transistor. Wherever you are

junction transistor. Wherever you are having low voltage, you are having field

having low voltage, you are having field effect transistors. Right? As I said,

effect transistors. Right? As I said, diodes can only turn on. You cannot turn

diodes can only turn on. You cannot turn it off turn off a diode. Whereas a

it off turn off a diode. Whereas a transistor, you can turn it on and turn

transistor, you can turn it on and turn it off according to your requirement.

it off according to your requirement. Okay. So the there are some unique

Okay. So the there are some unique functions of transistor that is they are

functions of transistor that is they are controlling loads by controlling its

controlling loads by controlling its current switching on and off generate

current switching on and off generate signal that is pulse with modulation. it

signal that is pulse with modulation. it can generate signal to drive any

can generate signal to drive any circuit. So these are the two different

circuit. So these are the two different uh switches used in all electronic

uh switches used in all electronic circuits

circuits and transformers. So you need to know

and transformers. So you need to know know about the transformers essentials

know about the transformers essentials around these electronic components. So

around these electronic components. So far we have seen about electronic

far we have seen about electronic components and we also know about we

components and we also know about we should also know about some essentials

should also know about some essentials which are found around the electronic

which are found around the electronic components. This is transformers. So I

components. This is transformers. So I hope you know you have seen the

hope you know you have seen the transformers. Anyhow I will just give a

transformers. Anyhow I will just give a brief introduction as a basic level. So

brief introduction as a basic level. So transformer works on the principle of

transformer works on the principle of Faraday's law of electromagnetic

Faraday's law of electromagnetic induction. So that is called as mutual

induction. So that is called as mutual induction. Transformer is nothing

induction. Transformer is nothing basically it has a core and you have a

basically it has a core and you have a primary side and an indu uh secondary

primary side and an indu uh secondary side. So primary side you have windings,

side. So primary side you have windings, secondary side you have windings. So in

secondary side you have windings. So in primary side if you give voltage in

primary side if you give voltage in secondary side mutually it will induce

secondary side mutually it will induce the same voltage on the secondary side.

the same voltage on the secondary side. So it actually uh uses to transmit the

So it actually uh uses to transmit the AC power from one point to the other

AC power from one point to the other point. So the transformer can be either

point. So the transformer can be either of two types. It can be the voltage can

of two types. It can be the voltage can be step up or step down transformer. If

be step up or step down transformer. If the input wtage is lower than the output

the input wtage is lower than the output wtage and the output wtage is higher

wtage and the output wtage is higher then that is called a step up

then that is called a step up transformer. If your input wtage is

transformer. If your input wtage is higher and the output wtage is lower

higher and the output wtage is lower then that is called a step down

then that is called a step down transformer. You can step up and step

transformer. You can step up and step down the voltage by means of number of

down the voltage by means of number of turns. So in the primary side if the

turns. So in the primary side if the turns is higher and in the secondary

turns is higher and in the secondary side if the turns is lower then the

side if the turns is lower then the voltage will get reduced. In the primary

voltage will get reduced. In the primary side the voltage uh the number of turns

side the voltage uh the number of turns is higher uh lower and the secondary

is higher uh lower and the secondary side if the number of turns is higher

side if the number of turns is higher then that it is called a step up

then that it is called a step up transformer. Your output wtage will be

transformer. Your output wtage will be much higher than your input voltage.

much higher than your input voltage. Okay. So this is the job of a transmit

Okay. So this is the job of a transmit transformer. The transformer actually

transformer. The transformer actually what it does is it transmits the AC

what it does is it transmits the AC power from one point to the other point.

power from one point to the other point. either it can increase the voltage or

either it can increase the voltage or decrease the voltage by with reference

decrease the voltage by with reference to its input. So this is called as step

to its input. So this is called as step up and step down transformer. Right?

It also and the unique uh function is it actually provides the isolation between

actually provides the isolation between the components. So since if you you if

the components. So since if you you if you are using a transformer in the load

you are using a transformer in the load side if you have any problem your input

side if you have any problem your input will not get affected because it is

will not get affected because it is actually the energy is transmitted

actually the energy is transmitted through mutual induction only. So if you

through mutual induction only. So if you are having any problem in the input side

are having any problem in the input side it will not affect the load side. If you

it will not affect the load side. If you are having any problem in the load side

are having any problem in the load side it will not affect the input side. So

it will not affect the input side. So the power is actually transmitted in an

the power is actually transmitted in an isolated mode. So if you though you

isolated mode. So if you though you since you are transmitting the power in

since you are transmitting the power in an isolated mode if the fault in one one

an isolated mode if the fault in one one side that is primary side will not

side that is primary side will not affect the secondary side. The power

affect the secondary side. The power fault at the secondary side will not

fault at the secondary side will not affect the primary side. This is the

affect the primary side. This is the unique feature of the transform. Right?

unique feature of the transform. Right? Next the integrated circuit that is

Next the integrated circuit that is IC's. Okay. So these are IC's. It is

IC's. Okay. So these are IC's. It is encapsulates most common electronic

encapsulates most common electronic components connected by a tiny gold or

components connected by a tiny gold or aluminum OS to perform unique functions.

aluminum OS to perform unique functions. Okay. Many logical circuits or logical

Okay. Many logical circuits or logical operations or any electronic circuit can

operations or any electronic circuit can be fabricated within this IC's or

be fabricated within this IC's or programmed within this IC's. And if you

programmed within this IC's. And if you connect this IC have pins. Okay. So

connect this IC have pins. Okay. So these pins will give like pin

these pins will give like pin configuration. If you see any IC you

configuration. If you see any IC you have a pin configuration you have a pin

have a pin configuration you have a pin diagram. that pin diagram will actually

diagram. that pin diagram will actually show you like what are the components

show you like what are the components there inside this IC. So this actually

there inside this IC. So this actually reduces the space of the electronic

reduces the space of the electronic circuits. So if you connect number of

circuits. So if you connect number of electronic components or you are

electronic components or you are connecting using wires or layout

connecting using wires or layout something to connect to these electronic

something to connect to these electronic components actually the circuit becomes

components actually the circuit becomes huger. So to reduce the size of the

huger. So to reduce the size of the circuit what you can do is you can just

circuit what you can do is you can just encapsulate all the electronic circuit

encapsulate all the electronic circuit by means of this type of integrated

by means of this type of integrated circuit. Uh so that the space of the

circuit. Uh so that the space of the electronic circuits will get reduced and

electronic circuits will get reduced and uh moreover the wire connections also

uh moreover the wire connections also can be reduced by using this types of

can be reduced by using this types of IC's. Okay. So the modern form of this

IC's. Okay. So the modern form of this IC's can be called as the microchips or

IC's can be called as the microchips or this processes. Right. So if you want to

this processes. Right. So if you want to have uh

have uh the chips as any input and any type of

the chips as any input and any type of output. So if you want to make any

output. So if you want to make any electronic circuit you can just

electronic circuit you can just fabricate by this in in types of uh IC's

fabricate by this in in types of uh IC's and you can embed it in your uh boards.

and you can embed it in your uh boards. So this is the actually the job of an

So this is the actually the job of an IC. So any type of logic circuit or any

IC. So any type of logic circuit or any if you want want to perform any timing

if you want want to perform any timing circuits like PWM signals or something

circuits like PWM signals or something PWM generator or something like that you

PWM generator or something like that you can just frame a circuit and you can

can just frame a circuit and you can convert it into an integrated circuit

convert it into an integrated circuit and make it as an uh IC that is

and make it as an uh IC that is integrated circuit. So these are the

integrated circuit. So these are the powerhouses of the electronic circuits.

powerhouses of the electronic circuits. So it can if you want to have mixer type

So it can if you want to have mixer type of uh signals for example analog signal,

of uh signals for example analog signal, digital signal or if you want to have

digital signal or if you want to have any communication signal all type of

any communication signal all type of signals can be connect given as an input

signals can be connect given as an input and taken as an output from this inter

and taken as an output from this inter IC. So these are the uh another uh

IC. So these are the uh another uh essential component which is associated

essential component which is associated with the your electronic components.

with the your electronic components. This can communicate with electrical

This can communicate with electrical component and electronic component.

component and electronic component. Right? So both can be communicated by

Right? So both can be communicated by means of this IC's.

means of this IC's. Next batteries. So the batteries are as

Next batteries. So the batteries are as I have said batteries provide the energy

I have said batteries provide the energy to the circuit and uh inside the battery

to the circuit and uh inside the battery you have chemical energy. These chemical

you have chemical energy. These chemical energies are converted to a necessary

energies are converted to a necessary electrical quantity to give the power to

electrical quantity to give the power to the supply. So these are the another

the supply. So these are the another component which is related to uh energy

component which is related to uh energy energy sources.

energy sources. Next we are coming into

Next we are coming into electric switches and its circuit. The

electric switches and its circuit. The circuit uh within the so far we have

circuit uh within the so far we have studied some uh basic essentials right

studied some uh basic essentials right actually now only we are coming into the

actually now only we are coming into the working of that circuit that uh switches

working of that circuit that uh switches that components how it is working.

that components how it is working. Coming to diode right coming to diode

Coming to diode right coming to diode what you are going to understand here is

what you are going to understand here is so now we are going to see in how the

so now we are going to see in how the diode is working as a component we have

diode is working as a component we have se seen already now I I'm going to see

se seen already now I I'm going to see like uh how it is working so as I said

like uh how it is working so as I said uh di means two or means electrodes so

uh di means two or means electrodes so two electrodes that is called as

two electrodes that is called as actually the diode and uh it allows the

actually the diode and uh it allows the current to flow easily in one direction

current to flow easily in one direction So if you see this is the symbol of

So if you see this is the symbol of diode in a circuit. So it has a

diode in a circuit. So it has a component anode and it has a component

component anode and it has a component cathode. Right? Now if you see a real

cathode. Right? Now if you see a real time of diode it will be in like this

time of diode it will be in like this only. How to identify the anode and

only. How to identify the anode and cathode means you will be seeing a

cathode means you will be seeing a single line here and that terminal it is

single line here and that terminal it is called as the cathode. The other

called as the cathode. The other terminal is called as anode. Right?

terminal is called as anode. Right? So this anode is to be connected to the

So this anode is to be connected to the positive of your battery and uh that is

positive of your battery and uh that is energy source and this negative should

energy source and this negative should you should connected to the negative

you should connected to the negative then only the current flow will be

then only the current flow will be there. Instead if you are making a

there. Instead if you are making a change in the connection then there will

change in the connection then there will not be any current flow. Okay. So if you

not be any current flow. Okay. So if you give positive to the positive terminal

give positive to the positive terminal and the negative cathode to the negative

and the negative cathode to the negative terminal then that is called as forward

terminal then that is called as forward bias. Okay. So as you study about the

bias. Okay. So as you study about the working of the diode, you'll understand

working of the diode, you'll understand the what is forward bias and reverse

the what is forward bias and reverse bias. But

bias. But as a single uh point what I can say is

as a single uh point what I can say is that if you connect the anode to the

that if you connect the anode to the positive terminal of the battery and

positive terminal of the battery and negative terminal to cathode to the

negative terminal to cathode to the negative terminal of the battery then

negative terminal of the battery then that is called as forward bias. Instead

that is called as forward bias. Instead if you are connecting the positive

if you are connecting the positive terminal to the cathode and negative

terminal to the cathode and negative terminal to the anode then that is

terminal to the anode then that is called as the reverse bias. So generally

called as the reverse bias. So generally you have to forward bias you should not

you have to forward bias you should not use reverse bias right. So if you use

use reverse bias right. So if you use the reverse bias the device may blow.

the reverse bias the device may blow. So these are the configurations in which

So these are the configurations in which you can find uh diodes. So practically

you can find uh diodes. So practically the diode is available in different

the diode is available in different types of configuration. So this is

types of configuration. So this is called as metal case and this is called

called as metal case and this is called a stud mount and this is called as a

a stud mount and this is called as a plastic case uh diode with bands and

plastic case uh diode with bands and this is a plastic case with camford and

this is a plastic case with camford and this is a glass case. So the diodes come

this is a glass case. So the diodes come in any form of uh thing based upon your

in any form of uh thing based upon your application and where you are going to

application and where you are going to mount the diode and how to how you going

mount the diode and how to how you going to use this diode. You can use any

to use this diode. You can use any configuration of the diode. In all the

configuration of the diode. In all the configurations you'll get that uh

configurations you'll get that uh particular value operating wtages and

particular value operating wtages and current voltages but based upon your

current voltages but based upon your application you can choose like what

application you can choose like what type of configuration you're going to

type of configuration you're going to use. Right. Right.

use. Right. Right. Here how to check the diode. Okay. So if

Here how to check the diode. Okay. So if it is reverse bias that is here you can

it is reverse bias that is here you can see the positive is connected to the

see the positive is connected to the negative terminal and negative is

negative terminal and negative is connected to the positive terminal then

connected to the positive terminal then that is negative then it is reverse

that is negative then it is reverse bias. So you cannot see a any value in

bias. So you cannot see a any value in your multimeter. So if you connect it

your multimeter. So if you connect it correctly positive to the positive

correctly positive to the positive terminal and negative to the negative

terminal and negative to the negative terminal you the you can see the value

terminal you the you can see the value is getting readed and you'll be having a

is getting readed and you'll be having a hearing a single beep sound in your

hearing a single beep sound in your multimeter. Right? So this is how you

multimeter. Right? So this is how you have to measure and check whether the

have to measure and check whether the diode is working or not. This is at

diode is working or not. This is at rated current and it is a good diode.

rated current and it is a good diode. Now

Now if the same diode is in faulty

if the same diode is in faulty condition. Okay. If it is faulty. Now if

condition. Okay. If it is faulty. Now if you connect it like positive to the

you connect it like positive to the positive and negative to the negative

positive and negative to the negative you don't have any sort of uh reading

you don't have any sort of uh reading there. Uh now if you change it in uh

there. Uh now if you change it in uh different way then also you can see you

different way then also you can see you cannot show any current value that is

cannot show any current value that is understood like the diode is faulty and

understood like the diode is faulty and previously you heard a single beep sound

previously you heard a single beep sound right now you'll be having a continuous

right now you'll be having a continuous beep sound because of it short circuit.

beep sound because of it short circuit. Okay. So in that scenario you can

Okay. So in that scenario you can understand like your diode is getting

understand like your diode is getting faulty and you cannot use that diode. So

faulty and you cannot use that diode. So this is how you can check the diode at

this is how you can check the diode at normal condition and faulty condition.

normal condition and faulty condition. Right

Right now how this diodes are working to

now how this diodes are working to understand that you need to have some

understand that you need to have some prerequisite on the semiconductor. So

prerequisite on the semiconductor. So what is a semiconductor? Okay so there

what is a semiconductor? Okay so there are certain type of material called

are certain type of material called insulator and conductor. So generally

insulator and conductor. So generally you know about insulator. Insulator

you know about insulator. Insulator doesn't allow current to pass through

doesn't allow current to pass through it. That type of material are called as

it. That type of material are called as insulator. If you take a current certain

insulator. If you take a current certain materials will allow electricity to pass

materials will allow electricity to pass through it. That is called as conductor.

through it. That is called as conductor. Right? So what actually means is that in

Right? So what actually means is that in an insulator this is a energy band

an insulator this is a energy band diagram that you have valance band and

diagram that you have valance band and conduction band. If the band gap is

conduction band. If the band gap is higher then that is called as insulator.

higher then that is called as insulator. So the electrons has to flow from

So the electrons has to flow from valance band to conduction band. Then

valance band to conduction band. Then only the flow of electricity will

only the flow of electricity will happen. Current will happen. So since

happen. Current will happen. So since this insulator band gap is huge, there

this insulator band gap is huge, there is the chance of electrons to travel to

is the chance of electrons to travel to the conduction band is less. So they

the conduction band is less. So they don't for the current will not flow

don't for the current will not flow from. So electrons is are not flowing.

from. So electrons is are not flowing. Since the electrons are not flowing,

Since the electrons are not flowing, current will not flow. So there is no

current will not flow. So there is no flow of current. So they are called as

flow of current. So they are called as insulator. Whereas if you take the

insulator. Whereas if you take the conducting materials, these conduction

conducting materials, these conduction band and valance band are touched each

band and valance band are touched each other. You don't find any band gap. So

other. You don't find any band gap. So the electrons will easily flow from the

the electrons will easily flow from the valance band to conduction band. So the

valance band to conduction band. So the conduction will happen. So it is called

conduction will happen. So it is called as conductors. Now what are

as conductors. Now what are semiconductors? Semiconductors have you

semiconductors? Semiconductors have you you have electrons in the valance band

you have electrons in the valance band and you have a conduction band. The band

and you have a conduction band. The band gap between the conduction band and

gap between the conduction band and balance band was huge in case of an

balance band was huge in case of an insulator whereas it is very thin in a

insulator whereas it is very thin in a place of semiconductors. All these types

place of semiconductors. All these types of materials only they are materials.

of materials only they are materials. Now if I give any temperature

Now if I give any temperature disturbances now this band gap will get

disturbances now this band gap will get reduced and the electrons will stand to

reduced and the electrons will stand to travel from valance band to elect

travel from valance band to elect electron band. Okay. So what I can sum

electron band. Okay. So what I can sum up is that semiconductors are generally

up is that semiconductors are generally insulator but when you give any

insulator but when you give any temperature disturbances by means of

temperature disturbances by means of voltages at that time electrons will

voltages at that time electrons will start to flow from valance band to the

start to flow from valance band to the conduction band. So they behave as a

conduction band. So they behave as a conductor. So generally they are

conductor. So generally they are insulator but if you give voltage if you

insulator but if you give voltage if you give a s small voltage and make it

give a s small voltage and make it thermally initiated the electrons will

thermally initiated the electrons will start to flow from balance band to

start to flow from balance band to electro band and they convert into a

electro band and they convert into a conductor right. So this type of giving

conductor right. So this type of giving voltage to them is called as biasing

voltage to them is called as biasing right. So when you bias it properly it

right. So when you bias it properly it will actually turn it as a conductor.

will actually turn it as a conductor. When you don't bias it will serve as an

When you don't bias it will serve as an insulator. Okay. So in this type of

insulator. Okay. So in this type of semiconductors are divided into two

semiconductors are divided into two types that is intrinsic type and

types that is intrinsic type and extrinsic type. In extrinsic type you

extrinsic type. In extrinsic type you have P type and N type. Intrinsic type

have P type and N type. Intrinsic type of conductors semiconductors are called

of conductors semiconductors are called as pure form of semiconductors. So they

as pure form of semiconductors. So they we will not use intrinsic type of

we will not use intrinsic type of semiconductor to fabricate a switch. We

semiconductor to fabricate a switch. We use actually a extrinsic type of

use actually a extrinsic type of semiconductor. So what are extrinsic

semiconductor. So what are extrinsic type of semiconductors? It is impure

type of semiconductors? It is impure form of semiconductors. It is not a

form of semiconductors. It is not a purest form. They will add impurities to

purest form. They will add impurities to the intrinsic semiconductors to make it

the intrinsic semiconductors to make it as an extensic type of semiconductor. So

as an extensic type of semiconductor. So that from this extent type also you have

that from this extent type also you have P type and N type extend type of

P type and N type extend type of semiconductor. Right? So what are

semiconductor. Right? So what are intrinsic type and extent type? If you

intrinsic type and extent type? If you see the difference okay so the

see the difference okay so the semiconducting material we are taking

semiconducting material we are taking example as silicon and germanmanium. So

example as silicon and germanmanium. So I I am taking a silicon over here. So

I I am taking a silicon over here. So every component here if you see here it

every component here if you see here it is silicon type. So since it is a

is silicon type. So since it is a silicon type you don't find any free

silicon type you don't find any free electrons or hole. So you don't have any

electrons or hole. So you don't have any free electrons or hole. If I want to

free electrons or hole. If I want to what are this electrons and hole means

what are this electrons and hole means electrons and holes okay are surrounding

electrons and holes okay are surrounding this silicon you have all type of

this silicon you have all type of valence bands. Okay you you can see

valence bands. Okay you you can see electrons four electrons they are

electrons four electrons they are actually a tetraalent component. So you

actually a tetraalent component. So you have four electrons around it. If I have

have four electrons around it. If I have all silicon around surrounding the

all silicon around surrounding the silicon I have only electrons. I don't

silicon I have only electrons. I don't find a hole. Okay. Electrons when they

find a hole. Okay. Electrons when they will move means if they find any hole.

will move means if they find any hole. If they find any hole these electrons

If they find any hole these electrons will come and sit in the holes. This is

will come and sit in the holes. This is how the flow of electrons is made. If

how the flow of electrons is made. If the electrons are flowing then only the

the electrons are flowing then only the current will also flow. If electrons are

current will also flow. If electrons are flowing from negative to positive

flowing from negative to positive current will flow from positive to

current will flow from positive to negative. So now what I am doing is that

negative. So now what I am doing is that I am making a process. I'm adding a

I am making a process. I'm adding a impur that is I'm converting the

impur that is I'm converting the intrinsic type of semiconductor to

intrinsic type of semiconductor to extrinsic type of semiconductor. The

extrinsic type of semiconductor. The process of adding impurities to the

process of adding impurities to the intrinsic type of semiconductor is

intrinsic type of semiconductor is called as doping. Okay. Now what I'm

called as doping. Okay. Now what I'm doing is I'm introducing some other

doing is I'm introducing some other component or some other type of material

component or some other type of material along with the silicon. that is I will

along with the silicon. that is I will add arsenic or boron to create four free

add arsenic or boron to create four free electrons or holes. So if I create free

electrons or holes. So if I create free electrons or holes then only I can make

electrons or holes then only I can make the electrons to move around. If I make

the electrons to move around. If I make the electrons to move around then only

the electrons to move around then only we will be actually make the current to

we will be actually make the current to flow from positive to negative right so

flow from positive to negative right so for that what I am doing is that

for that what I am doing is that I am adding arsenic now. So arsenic will

I am adding arsenic now. So arsenic will have five electrons around it. Whereas

have five electrons around it. Whereas silicon is having four electrons right I

silicon is having four electrons right I am now adding a five electronic

am now adding a five electronic component towards it. So I am creating

component towards it. So I am creating free electron. So I when I'm creating a

free electron. So I when I'm creating a free electron the electrons will try to

free electron the electrons will try to move around to search for a hole. So

move around to search for a hole. So that I making the electron to move

that I making the electron to move around. So the my electricity will flow.

around. So the my electricity will flow. Now I am adding asenic means I'm getting

Now I am adding asenic means I'm getting free electrons that is it is pentavalent

free electrons that is it is pentavalent component. So free electrons are there.

component. So free electrons are there. Now the electrons will start to move.

Now the electrons will start to move. Here the majority carrier is electrons.

Here the majority carrier is electrons. So if I am adding more more number of

So if I am adding more more number of electrons and creating more number of

electrons and creating more number of free electrons I that is called as n

free electrons I that is called as n type of semiconductors. Okay. Instead if

type of semiconductors. Okay. Instead if I'm adding boron that is trialent

I'm adding boron that is trialent component. So silicon is having four

component. So silicon is having four electron around it. Boron is having only

electron around it. Boron is having only three electron. So it is having an extra

three electron. So it is having an extra hole. Now what happens? Now any extra

hole. Now what happens? Now any extra electrons from the silicon will try to

electrons from the silicon will try to occupy this hole. Now this is creating a

occupy this hole. Now this is creating a hole. Now another electron will flow to

hole. Now another electron will flow to this hole. Now I'm making the electrons

this hole. Now I'm making the electrons to flow towards the hole. Now also I'm

to flow towards the hole. Now also I'm creating like a chance to electrons to

creating like a chance to electrons to move. Now what happens? Now electron I'm

move. Now what happens? Now electron I'm creating more holes and more electrons.

creating more holes and more electrons. In this both the cases if I am having

In this both the cases if I am having more free electrons and I'm having

more free electrons and I'm having minimum holes then that is called as n

minimum holes then that is called as n type of semiconductors. Instead if I am

type of semiconductors. Instead if I am having more holes and less number of

having more holes and less number of free electrons then that is called as P

free electrons then that is called as P type of semiconductors. So this thing

type of semiconductors. So this thing also you have to keep in your mind. So

also you have to keep in your mind. So basic difference between the N type and

basic difference between the N type and P type of semiconductor is in N type of

P type of semiconductor is in N type of semiconductor the majority carrier is

semiconductor the majority carrier is electrons and minority carriers is coal.

electrons and minority carriers is coal. Whereas in P type of semiconductors the

Whereas in P type of semiconductors the majority carriers is coal and the

majority carriers is coal and the minority carriers are electrons. Now you

minority carriers are electrons. Now you have to understand what is the P type of

have to understand what is the P type of semiconductor and N type of

semiconductor and N type of semiconductor. Now you understood P type

semiconductor. Now you understood P type of N type of semiconductor. Isn't it?

of N type of semiconductor. Isn't it? Now the next step what I'm going to do

Now the next step what I'm going to do is I am going to bring this P type of

is I am going to bring this P type of semiconductor and N type of

semiconductor and N type of semiconductor together. Now you all know

semiconductor together. Now you all know P type of semiconductor is having

P type of semiconductor is having majority as holes and N type of

majority as holes and N type of semiconductor is having majority of

semiconductor is having majority of electrons. Now all the majority of holes

electrons. Now all the majority of holes from this P and the majority carriers of

from this P and the majority carriers of electrons will try to recombine now

electrons will try to recombine now because this is having more holes. This

because this is having more holes. This is having more electrons. Now these

is having more electrons. Now these electrons free electrons will try to

electrons free electrons will try to occupy the holes at this position. Now

occupy the holes at this position. Now they try to recombine. Now they

they try to recombine. Now they recombine and they form a region like

recombine and they form a region like this and this region is called as

this and this region is called as depletion layer. Right? Now here you can

depletion layer. Right? Now here you can see the negative terminal at this point

see the negative terminal at this point and here you can see the positive

and here you can see the positive terminal as this point. Actually this

terminal as this point. Actually this point is the positive terminal and this

point is the positive terminal and this point is the negative terminal. But they

point is the negative terminal. But they are interchanged and swapped in this

are interchanged and swapped in this region. Here you can see the negative

region. Here you can see the negative terminals here and positive terminal

terminals here and positive terminal here. So if you check this this serves

here. So if you check this this serves as the barrier for this actually actual

as the barrier for this actually actual voltage. So this region is also called

voltage. So this region is also called as barrier potential region. Okay. Now

as barrier potential region. Okay. Now this is positive and this is negative as

this is positive and this is negative as a whole. Whereas inside this region what

a whole. Whereas inside this region what you can see is that here as negative and

you can see is that here as negative and here as positive.

here as positive. Now this region is called as depletion

Now this region is called as depletion region. Now this depletion region will

region. Now this depletion region will be there when you buy a diode. Now here

be there when you buy a diode. Now here you having a P and here you are having a

you having a P and here you are having a N type of material and here you have a

N type of material and here you have a junction. So this is called as N PN

junction. So this is called as N PN junction diode. Okay. If you buy a diode

junction diode. Okay. If you buy a diode from a

from a from a market. Okay. Now these depletion

from a market. Okay. Now these depletion layers are there inbuilt inside it.

layers are there inbuilt inside it. Okay. Okay, if I buy a diode from a

Okay. Okay, if I buy a diode from a market, you need not do anything. This

market, you need not do anything. This depletion layer is formed by itself.

depletion layer is formed by itself. Okay, now what I have to give now what I

Okay, now what I have to give now what I have to do is that now I have to give a

have to do is that now I have to give a voltage. Okay, now when I give a

voltage. Okay, now when I give a positive voltage to the P P type of

positive voltage to the P P type of semiconductor and negative voltage to

semiconductor and negative voltage to the N type of semiconductor. Now

the N type of semiconductor. Now actually I'm doing a forward bias. Now

actually I'm doing a forward bias. Now when I do a forward bias, what happens?

when I do a forward bias, what happens? This depletion layer as I increase the

This depletion layer as I increase the battery voltage from zero to one zero to

battery voltage from zero to one zero to one point. Now the depletion layer is

one point. Now the depletion layer is decreasing decreasing decreasing as I

decreasing decreasing decreasing as I increase my battery voltage. As I

increase my battery voltage. As I increase my battery voltage the

increase my battery voltage the depletion layer is getting reduced and

depletion layer is getting reduced and at one particular point the depletion

at one particular point the depletion layer itself is not there and then my

layer itself is not there and then my current will flow from positive to

current will flow from positive to negative. Similarly my electrons will

negative. Similarly my electrons will flow from negative to positive. So now

flow from negative to positive. So now my switch has started to working. Now

my switch has started to working. Now the switch is conducting. My current is

the switch is conducting. My current is flowing from positive to negative at

flowing from positive to negative at this point. This is called as forward

this point. This is called as forward bias. Right? Now similarly

bias. Right? Now similarly when I change the battery wtage from

when I change the battery wtage from negative to positive. What happens? My

negative to positive. What happens? My depletion layer is still getting

depletion layer is still getting enlarged and wider. And at one

enlarged and wider. And at one particular point my switches start

particular point my switches start stopped working and switches not at all

stopped working and switches not at all working. my current is not at all

working. my current is not at all flowing. This is called as reverse bias.

flowing. This is called as reverse bias. Reverse bias generally we don't do. We

Reverse bias generally we don't do. We do only forward bias to make the switch

do only forward bias to make the switch to work. Right? Now I am asking if I

to work. Right? Now I am asking if I want to switch on my diode. Now what I

want to switch on my diode. Now what I should do? I should do forward bias.

should do? I should do forward bias. Correct? Similarly, when I want to turn

Correct? Similarly, when I want to turn off my device, now what I do?

off my device, now what I do? Just give me your answer in your chat

Just give me your answer in your chat section.

If I my question is when I want to turn off my diode, what I should do?

So I am receiving more number of comments like reverse bias. So what I'm

comments like reverse bias. So what I'm saying now is

saying now is you should not perform reverse bias.

you should not perform reverse bias. Okay? If you want to turn on the di

Okay? If you want to turn on the di diode, you just give the battery

diode, you just give the battery voltage. Okay? If you want to turn off

voltage. Okay? If you want to turn off the diode, don't give this battery

the diode, don't give this battery wtage. That is how the diode should be

wtage. That is how the diode should be turned off. You should not give reverse

turned off. You should not give reverse bias. Reverse bias operation is for

bias. Reverse bias operation is for different application, not for your

different application, not for your switching application. So what you have

switching application. So what you have to understand is that

to understand is that when I want to switch on my diode, I

when I want to switch on my diode, I just give battery voltage from zero. As

just give battery voltage from zero. As I give my battery voltage, my current is

I give my battery voltage, my current is also increasing, increasing, increasing.

also increasing, increasing, increasing. And at one point the current is reaching

And at one point the current is reaching its maximum point above which though you

its maximum point above which though you increase your voltage, your voltage will

increase your voltage, your voltage will never increase. Instead, your current

never increase. Instead, your current only will increase. Okay? Right? If you

only will increase. Okay? Right? If you want to turn off this diode, you just

want to turn off this diode, you just give

give stop giving the forward bias. You should

stop giving the forward bias. You should not do your reverse bias. Okay? Reverse

not do your reverse bias. Okay? Reverse bias connection is not for your

bias connection is not for your switching operation. So if you give your

switching operation. So if you give your reverse bias, you get more number of

reverse bias, you get more number of breakdown voltages. So switches may

breakdown voltages. So switches may after extension of voltage, the switch

after extension of voltage, the switch may also blow off. Okay? So you should

may also blow off. Okay? So you should not give reverse bias. So if I want to

not give reverse bias. So if I want to turn off my diode, what I should do? I

turn off my diode, what I should do? I should just stop giving my forward bias.

should just stop giving my forward bias. So in the very beginning I said you

So in the very beginning I said you right diode you can only turn on you you

right diode you can only turn on you you cannot turn off. So the meaning of it is

cannot turn off. So the meaning of it is when I give forward bias you just

when I give forward bias you just understood my depletion layer is getting

understood my depletion layer is getting reduced reduced reduced and one

reduced reduced reduced and one particular point my depletion layer will

particular point my depletion layer will not be there and the current will start

not be there and the current will start to flow from positive to negative

to flow from positive to negative correct when I turn off I'm just

correct when I turn off I'm just stopping my forward bias voltage. Now

stopping my forward bias voltage. Now what happens is still my diode is

what happens is still my diode is actually though I stop my voltage still

actually though I stop my voltage still my diode is on

my diode is on unless and until the depletion layer is

unless and until the depletion layer is regaining it to its original position my

regaining it to its original position my diode will be in on position only so

diode will be in on position only so only I said you can just turn on your

only I said you can just turn on your diode but you cannot turn off your diode

diode but you cannot turn off your diode because the turn off period is not

because the turn off period is not depending on you it is depending upon

depending on you it is depending upon the nature of the diode which you are

the nature of the diode which you are purchasing because it has to regain to

purchasing because it has to regain to its original position. Unless and until

its original position. Unless and until it is gain to going to its original

it is gain to going to its original position your diode you cannot tell it

position your diode you cannot tell it is off situation. So only it is called

is off situation. So only it is called as uncontrolled switches right. I think

as uncontrolled switches right. I think I am very clear in this point and you

I am very clear in this point and you also understand understood the point

also understand understood the point very clearly. If you understood this

very clearly. If you understood this point all type of till this point till

point all type of till this point till this point if you understood all the

this point if you understood all the working of capacitor resistor inductor

working of capacitor resistor inductor and this P and junction diode any sort

and this P and junction diode any sort of circuit will be easy for you. Is that

of circuit will be easy for you. Is that clear? Is that clear? So if you

clear? Is that clear? So if you understood these working of this

understood these working of this capacitor, working of this resistor,

capacitor, working of this resistor, working of this inductor and the how the

working of this inductor and the how the voltage and circuit will travel in a

voltage and circuit will travel in a circuit, you are good to go. You don't

circuit, you are good to go. You don't require any teacher. You can analyze any

require any teacher. You can analyze any type of circuit and you can analyze any

type of circuit and you can analyze any type of understand the working of any

type of understand the working of any type of circuit.

type of circuit. Is that clear? So now we are going in

Is that clear? So now we are going in for another circuit that another type of

for another circuit that another type of switch that is three terminal devices

switch that is three terminal devices that is called as transistor.

that is called as transistor. Okay. What is a transistor? It is a

Okay. What is a transistor? It is a three terminal devices. As I said

three terminal devices. As I said already in a diode you cannot turn off

already in a diode you cannot turn off but in a transistor you can turn on and

but in a transistor you can turn on and turn off according to your need. Right?

turn off according to your need. Right? So this is how you construct a

So this is how you construct a transistor. You know P type of material,

transistor. You know P type of material, you know N type of material and NP

you know N type of material and NP another P type of material. Right? Now

another P type of material. Right? Now you are making it as a two junction. You

you are making it as a two junction. You are creating a two junction just by

are creating a two junction just by making it into this arrangement. P N P

making it into this arrangement. P N P or N P N. So by like making like this

or N P N. So by like making like this you'll be able to make three terminals

you'll be able to make three terminals at each basis like see here emitter

at each basis like see here emitter base collector. Similarly here also

base collector. Similarly here also emitter base collector and you can

emitter base collector and you can create two junction one and two right.

create two junction one and two right. So you are technically if you see you

So you are technically if you see you are making the diode to make in this

are making the diode to make in this arrangement in a case of PNP whereas

arrangement in a case of PNP whereas like this in a case of a NPN transistor.

like this in a case of a NPN transistor. So this is the symbol of a transistor.

So this is the symbol of a transistor. Here you can see this is the symbol of a

Here you can see this is the symbol of a transistor. So which terminal is serving

transistor. So which terminal is serving in the center? It is called as base. In

in the center? It is called as base. In one terminal you can see the arrow mark.

one terminal you can see the arrow mark. The terminal which is having arrow mark

The terminal which is having arrow mark is called as emitter. The terminal which

is called as emitter. The terminal which is not having arrow mark is called as

is not having arrow mark is called as collector. Okay. So if the arrow mark is

collector. Okay. So if the arrow mark is entering towards the base then that is

entering towards the base then that is called as PNP type of transistor. If the

called as PNP type of transistor. If the arrow mark is leaving the base then that

arrow mark is leaving the base then that is called as NPN type of transistor.

is called as NPN type of transistor. Right? So if the current is entering

Right? So if the current is entering towards the base then that is that is

towards the base then that is that is actually denoted by this arrow. If the

actually denoted by this arrow. If the current is leaving the base that is

current is leaving the base that is denoted to this denoted by this arrow

denoted to this denoted by this arrow the arrow mark in the symbol actually

the arrow mark in the symbol actually denotes the current direction

denotes the current direction current direction. Okay. So here you can

current direction. Okay. So here you can see the voltages across two terminals we

see the voltages across two terminals we are having. Okay. So the voltage across

are having. Okay. So the voltage across this base and emitter is called as

this base and emitter is called as emitter base voltage. The voltage across

emitter base voltage. The voltage across base and collector is called as

base and collector is called as collector base voltage. The voltage

collector base voltage. The voltage across emitter and current is called as

across emitter and current is called as the emitter current wtage. So this is

the emitter current wtage. So this is how the voltage across different types

how the voltage across different types of transistors are identified and the

of transistors are identified and the current flowing through each line that

current flowing through each line that is emitter current, collector current

is emitter current, collector current and base current also flowing through

and base current also flowing through the circuit. Is that correct? Right now

the circuit. Is that correct? Right now this is the symbol of the uh circuit

this is the symbol of the uh circuit symbol of the bipolar junction

symbol of the bipolar junction transistor. So if you see the working

transistor. So if you see the working around here this is the internal term

around here this is the internal term internal diagram of a transistor. So I

internal diagram of a transistor. So I think I am on time now the time is still

think I am on time now the time is still I have 15 minutes so somehow I'll try to

I have 15 minutes so somehow I'll try to complete this uh transistor working in

complete this uh transistor working in another 10 minutes. So we can have a

another 10 minutes. So we can have a discussion like open forum discussion

discussion like open forum discussion for 5 to 2 minutes and we can end up

for 5 to 2 minutes and we can end up this session. So I'm just going with the

this session. So I'm just going with the flow and then you can ask your doubts at

flow and then you can ask your doubts at the end of the session. Now what I'm

the end of the session. Now what I'm going to do is that I'm going to forward

going to do is that I'm going to forward bias two junction and another junction

bias two junction and another junction I'm going to reverse bias. Here only I'm

I'm going to reverse bias. Here only I'm actually using the condition of reverse

actually using the condition of reverse bias not in the diode. Here I'm using

bias not in the diode. Here I'm using the condition for reverse bias because

the condition for reverse bias because I'm going to block the voltage at that

I'm going to block the voltage at that one point and I'm going to give the

one point and I'm going to give the voltage at another terminal. So what

voltage at another terminal. So what actually I'm doing is that I'm going to

actually I'm doing is that I'm going to forward bias at this terminal. Here you

forward bias at this terminal. Here you can see the base

can see the base the base and the base I am giving the

the base and the base I am giving the positive terminal that is P I'm giving a

positive terminal that is P I'm giving a positive terminal and N I am giving the

positive terminal and N I am giving the negative terminal. So I'm giving the

negative terminal. So I'm giving the voltage across base and emitter is

voltage across base and emitter is emitter base voltage. Here I'm actually

emitter base voltage. Here I'm actually forward biasing it. So here I'm going to

forward biasing it. So here I'm going to increase the voltage from zero to at

increase the voltage from zero to at whatever point I want. Similarly across

whatever point I want. Similarly across the capacitor and emitter I'm giving

the capacitor and emitter I'm giving another voltage source. Here I'm

another voltage source. Here I'm actually reverse biasing it. Here you

actually reverse biasing it. Here you see the P is connected to the negative

see the P is connected to the negative terminal and C is connected to the

terminal and C is connected to the negative positive terminal. Here you

negative positive terminal. Here you follow just the current values. Current

follow just the current values. Current is denoted by the letter I. Since the

is denoted by the letter I. Since the current is traveling towards the

current is traveling towards the emitter, I'm denoting is suffix E is

emitter, I'm denoting is suffix E is added to the current. Now I am

added to the current. Now I am I E. Right? Now the collector current I

I E. Right? Now the collector current I C. See I is denoted for current and the

C. See I is denoted for current and the suffix C is carrying over here towards

suffix C is carrying over here towards the base. You see current is coming here

the base. You see current is coming here and the I'm having the suffix B here.

and the I'm having the suffix B here. Okay. Now similarly wtage I have told

Okay. Now similarly wtage I have told already here you can see across base and

already here you can see across base and emitter I have connected the voltage. So

emitter I have connected the voltage. So my voltage V is denoted with the suffix

my voltage V is denoted with the suffix B base and emitter. Similarly you see

B base and emitter. Similarly you see here across the collector emitter wtage

here across the collector emitter wtage I'm collector and base I'm having the

I'm collector and base I'm having the voltage symbol and uh suffix I'm having

voltage symbol and uh suffix I'm having CB. Okay. Now I'm forward biasing at

CB. Okay. Now I'm forward biasing at this terminal and I am reverse biasing

this terminal and I am reverse biasing at this terminal. So what actually you

at this terminal. So what actually you have to understand by this bipolar

have to understand by this bipolar junction transistor is how it is working

junction transistor is how it is working is this is the input current right and

is this is the input current right and this is the output current. So the

this is the output current. So the current is entering towards the

current is entering towards the collector and leaving towards the

collector and leaving towards the emitter. Just you forget about this

emitter. Just you forget about this space. My logic should be like if I am

space. My logic should be like if I am using a switch the current from the

using a switch the current from the collector and the current to the emitter

collector and the current to the emitter leaving the current entering and leaving

leaving the current entering and leaving should be same. Then only I can say my

should be same. Then only I can say my switch is on. Correct. Here you see in

switch is on. Correct. Here you see in between I am having a base current.

between I am having a base current. Okay. So actually my emitter current is

Okay. So actually my emitter current is nothing but collector current plus this

nothing but collector current plus this base current. Now what I am doing is

base current. Now what I am doing is that by means of

that by means of base emitter wtage I'm giving my system

base emitter wtage I'm giving my system voltage and through my reverse bias

voltage and through my reverse bias voltage I am blocking the amount of base

voltage I am blocking the amount of base current flowing through it. Okay. Now

current flowing through it. Okay. Now what I'm doing is my emitter current is

what I'm doing is my emitter current is nothing but collector current plus base

nothing but collector current plus base current. Right? I am doing certain

current. Right? I am doing certain voltage increase in such a way that I am

voltage increase in such a way that I am bringing my base current to zero. So if

bringing my base current to zero. So if I bring my base current to zero, what

I bring my base current to zero, what happens? Ultimately my collector current

happens? Ultimately my collector current will be equal to emitter current. So

will be equal to emitter current. So initially my emitter current will be

initially my emitter current will be summation of base current plus collector

summation of base current plus collector current and I have both base current

current and I have both base current value also and collector current value

value also and collector current value also. over the course of time by

also. over the course of time by increasing my voltage what I'm doing is

increasing my voltage what I'm doing is I'm bringing this base current to zero.

I'm bringing this base current to zero. So if I bring my base current to zero

So if I bring my base current to zero what happens? Just my collector current

what happens? Just my collector current will be equal to the emitter current.

will be equal to the emitter current. Okay. So now the switch is on actually.

Okay. So now the switch is on actually. Okay. So since the switch is on my

Okay. So since the switch is on my current will flow from collector to

current will flow from collector to emitter current. So I hope you

emitter current. So I hope you understood like how the BJT is working.

understood like how the BJT is working. Very simple. I'm doing a certain

Very simple. I'm doing a certain operation so that I'm bringing my base

operation so that I'm bringing my base current to zero by what is that

current to zero by what is that operation? By increasing my emitter to

operation? By increasing my emitter to base wtage and my decreasing my voltage

base wtage and my decreasing my voltage to collector wtage. By doing that I am

to collector wtage. By doing that I am just bringing my base current to zero.

just bringing my base current to zero. If I bring my base current to zero, my

If I bring my base current to zero, my collector current will be equal to

collector current will be equal to emitter current and that makes the

emitter current and that makes the switch to on.

switch to on. Right now

Right now this is how the working principle as a

this is how the working principle as a circuit I just analyzing it. Now this is

circuit I just analyzing it. Now this is your symbol of your

your symbol of your BJT base collector emitter. So my

BJT base collector emitter. So my current has to flow from collector to

current has to flow from collector to emitter right this this is where I will

emitter right this this is where I will connect my load. This is where I am

connect my load. This is where I am connecting my load. So my current my

connecting my load. So my current my load is connected here. Now you see I'm

load is connected here. Now you see I'm just bringing my voltage to the base.

just bringing my voltage to the base. Here you have a resistor base resistor.

Here you have a resistor base resistor. Now what I have to do is that I have to

Now what I have to do is that I have to increase the resistor value. If I

increase the resistor value. If I increase the resistor value what

increase the resistor value what happens? My base current is getting

happens? My base current is getting blocked. So how I will increase my

blocked. So how I will increase my resistor? By increasing the voltage

resistor? By increasing the voltage across base and emitter. So as I

across base and emitter. So as I increase my voltage across base and

increase my voltage across base and emitter from zero to maximum, I am just

emitter from zero to maximum, I am just able to create a voltage drop across

able to create a voltage drop across this resistor which blocks this base

this resistor which blocks this base current. If I block this base current,

current. If I block this base current, my base current will become zero. Okay.

my base current will become zero. Okay. So how you can understand the transistor

So how you can understand the transistor switch is that as you make the base

switch is that as you make the base current to zero, the current from the

current to zero, the current from the collector will flow to the emitter and

collector will flow to the emitter and then the switch is getting on. So always

then the switch is getting on. So always the switch will be in on condition. But

the switch will be in on condition. But when you make the base current to zero

when you make the base current to zero then only the current will flow from

then only the current will flow from this point to this point. So the load

this point to this point. So the load will acquire the current. So as the load

will acquire the current. So as the load is acquiring the current what we can

is acquiring the current what we can understand is I I think my switch is on.

understand is I I think my switch is on. So this is how the switch is getting

So this is how the switch is getting operated. Right? This is the working

operated. Right? This is the working principle of BJT. Okay.

principle of BJT. Okay. Here you see

Here you see these are the different configurations

these are the different configurations of the BJT. Either you can take see here

of the BJT. Either you can take see here by making common base you make base as

by making common base you make base as the common and you make two wtages

the common and you make two wtages across base emitter wtage and base

across base emitter wtage and base collector voltage. Similarly what you

collector voltage. Similarly what you can do you can make the collector to be

can do you can make the collector to be a common terminal also. If I make the

a common terminal also. If I make the collector terminal to be common, the

collector terminal to be common, the voltage will be like voltage across B

voltage will be like voltage across B and base collector voltage and voltage

and base collector voltage and voltage collector and emitter. Similarly, what I

collector and emitter. Similarly, what I can make is I can make emitter also as a

can make is I can make emitter also as a common. So, if I make emitter as common,

common. So, if I make emitter as common, what I will do, I will have two wtages

what I will do, I will have two wtages to control here. Wtage across base and

to control here. Wtage across base and emitter and voltage across collector and

emitter and voltage across collector and emitter. Though I could

emitter. Though I could though I could connect both the voltages

though I could connect both the voltages what I am doing is why I should though I

what I am doing is why I should though I can make every term each and every

can make every term each and every terminal as uh common

terminal as uh common how I could differentiate as a switch

how I could differentiate as a switch operation. If I see in both all the

operation. If I see in both all the three combinations, all the three

three combinations, all the three configurations, these are the internal

configurations, these are the internal par parameters what how do they behave

par parameters what how do they behave just leave about all the voltage gain,

just leave about all the voltage gain, power gain and current gain. Just see

power gain and current gain. Just see only the input impedance and output

only the input impedance and output impedance. Okay, for a switch for a

impedance. Okay, for a switch for a semiconducting device to operate at the

semiconducting device to operate at the switch, the best quality is its input

switch, the best quality is its input impedance should be low and output

impedance should be low and output impedance should be high. So in this

impedance should be high. So in this three scenario three configurations in

three scenario three configurations in common base alone you can find your

common base alone you can find your input impedance is low and output

input impedance is low and output impedance is high. So for operating this

impedance is high. So for operating this BJT as a switch common base mode is the

BJT as a switch common base mode is the proper mode to choose. So in these three

proper mode to choose. So in these three configuration if you are going to

configuration if you are going to operate this transistor as a switch you

operate this transistor as a switch you should choose for common base mode. So

should choose for common base mode. So is that clear? So this is what you need

is that clear? So this is what you need to understand in BJT. So this this is

to understand in BJT. So this this is how the different types of other type of

how the different types of other type of switches like IGBT and I will tell about

switches like IGBT and I will tell about this field effect transistor also will

this field effect transistor also will work. Now I think the

work. Now I think the uh time is around 11:55 and your session

uh time is around 11:55 and your session will end by 12 automatically. So I think

will end by 12 automatically. So I think if you want to have any discussion you

if you want to have any discussion you can just open up in your uh chat box so

can just open up in your uh chat box so that I can clarify your doubts and we

that I can clarify your doubts and we can end up the session at 12.

can end up the session at 12. So you can just give your comments like

So you can just give your comments like uh what do you want to know you can

so I think you are really worried about my name and uh where do I work so I'll

my name and uh where do I work so I'll at the end of this session that is the

at the end of this session that is the fifth day I'll share my LinkedIn profile

fifth day I'll share my LinkedIn profile you can just go through it and you can

you can just go through it and you can find my these things

find my these things sir you can always end the session prior

sir you can always end the session prior to the schedule time kic okay that's

to the schedule time kic okay that's fine

fine I then I think my sessions are boring so

I then I think my sessions are boring so you are asking me to end up earlier or

you are asking me to end up earlier or what Karthik

uh PT will be shared from the academy I guess I'm ready to share my PPT based

guess I'm ready to share my PPT based upon the academy they will share if you

upon the academy they will share if you want

I don't have any notes I share only PPT so you and find my PPS

so you and find my PPS as your notes. You just uh through the

as your notes. You just uh through the AI tool which can just convert into

AI tool which can just convert into notes also if you want. Yeah.

So I think I am answering the sessions. I think we will end up the session here

I think we will end up the session here and we will con continue our afternoon

and we will con continue our afternoon session at 2.

Thank you for being with me. As the session is ending, you may just uh

go for your work and turn around. You'll meet I I'll be happy to meet you at

meet I I'll be happy to meet you at Yeah. Thank you.

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YouTube Transcript:Embedded Systems and Design & Development - Feb 23, 2026 | Morning | VisionAstraa EV Academy

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Embedded Systems and Design & Development - Feb 23, 2026 | Morning | VisionAstraa EV Academy