0:01 before I start off this video here is a
0:04 summary of current sensors and there are
0:06 different parameters for what I think is
0:08 important to be when considering what
0:10 type of contents you're going to use if
0:12 you came for this video for just a quick
0:14 overview here it is please pause the
0:16 video take a screenshot and you can find
0:17 out the different types of current
0:19 sensors they are in a brief and a brief
0:21 indication of how effective they are and
0:23 you can choose from there stick around
0:24 for the rest of the video to find out a
0:26 bit more into detail about three of them
0:29 I have spoken about I hope you enjoy the
0:31 rest of the video so here I am on a
0:34 website himaroni and it's a and here
0:39 I've got a Ina i n a169 analog DC
0:41 current Center breakout 60 volts 5A Max
0:43 this is something I've used a lot in my
0:46 own projects before that I've had to do
0:48 as a project for I had to test multiple
0:50 samples and I multiplexed them all into
0:52 the ADC of an Arduino to test the proof
0:54 of concept thing to see if we can
0:55 measure the resistance of these samples
0:57 with a voltage is applied to them and
0:59 whatnot and we use this to get the
1:01 accurating ohms saw do I know if it was
1:02 the right way there's probably so many
1:03 other better ways to do it but that's
1:04 the point besides the point of this
1:06 video taking a look at this this is
1:07 there are a few ways there are a few
1:08 ways to measure current and it can
1:10 either be indirect or directly in this
1:12 case this is a direct method because it
1:14 is literally passing through a shunt
1:15 resistor where you need to bulge the
1:17 wires and get thing in through it the
1:19 need to polish the wires and pass a
1:21 current through the shunt resistor here
1:22 if you do not know these shunt resistors
1:25 are current sense resistors otherwise
1:27 and they drop a voltage across it and it
1:29 usually picks it up through here and it
1:31 probably takes a reading out of it and
1:33 outputs it into your in the output as a
1:34 millivolt and then your ADC you can read
1:36 it so on so forth and you're thinking
1:39 okay so what I I could usually Implement
1:42 yes so could I implement this could I do
1:44 the exact same thing in in my project
1:46 yes you can you definitely can there's
1:49 no harm in that you definitely can do
1:51 that and we'll take a look at the data
1:53 sheet let's find out let's find out what
1:54 do you actually need here we are in the
1:57 data sheet i n a169 it's a high side
1:59 unipolar current shunt monitor why
2:03 voltage range tiny so salt 23 package
2:06 and use a variety of applications like I
2:07 said before I've used this a lot in the
2:08 past and it's brilliant absolutely
2:09 brilliant just to get something quick
2:12 and going easy easy to do so what are we
2:14 looking for when we come to this as I
2:16 said before these can be either indirect
2:19 or direct so first what type of method
2:20 do you want because then that's indirectly
2:21 indirectly
2:23 um might not be so invasive for your
2:24 purpose or something that's direct you
2:25 don't want you putting this in the
2:26 circuit or something take a look we're
2:28 going to be looking at a an indirect map
2:30 a few methods really throughout this
2:32 video so this is one method and you look
2:33 through it you're looking for the
2:34 operation you want to understand how
2:36 this device works so you can implement
2:38 it fairly straightforward the shunt goes
2:39 across here there's a load power supply
2:42 slide and externally to it through here
2:43 okay this will be the same one passes
2:45 through a shunt resistor and comes out
2:47 to your load gives you some values of
2:49 the voltage gain here of what you want
2:51 to expect and with the resistors it's
2:54 very easy very easy to set up and get
2:55 you going I would highly recommend you
2:58 read this part of the data sheet it
3:00 really really helps so I do highly
3:02 recommend it over here usually in these
3:03 days they always give some sort of
3:05 application and it's easy to get you
3:07 going see it's really that simple
3:10 nothing too complex about it again this
3:11 is one of the more popular ones so if
3:13 you just follows if you just followed
3:15 what it says you can easily implement
3:16 this and if you're really that lost
3:18 refer to these modules they they come
3:20 ready plug-in easy to use use that for
3:21 your proof of concept if that's what
3:23 you're doing or just copy the layout
3:25 design from this easy and these models
3:26 are not expensive the chip will be even
3:28 less from so expensive don't worry about
3:30 it so let's look at a different method
3:32 an indirect method for your project
3:35 let's take a look at this zmc t103c
3:37 current sensor module AC another popular
3:39 another quite popular current sense
3:41 module and this one I haven't been fond
3:43 of with the project that I am going into
3:45 but for your case if you're looking for
3:47 that Innovative so even the project I
3:48 plan to do is going for this week's off
3:50 purpose you can already see that we have
3:51 a donut shaped hole here and you can
3:53 really think oh I guess I'll Chuck the
3:55 wire through it yes that is exactly how
3:56 it does let's see how it works then
3:58 shall we so how is this actually working
4:00 I've got a brief dial diagram laid out
4:02 here and as you see the image is quite
4:04 self-explanatory so this would work by
4:06 first applying your wire through as for
4:07 reference through the the donut shape
4:09 conductor and by passing through this
4:11 wire it measures the change in the
4:13 magnetic field because it's an AC signal
4:15 and this would be act as your primary
4:17 coil now this is a current Transformer
4:18 so if you know how the basic operation
4:20 of transform work the same principles
4:22 apply your primary and secondary coil
4:24 and so this coil over here the secondary
4:26 one is essentially stepping it down from
4:27 your primary is it not smart and because
4:29 I said before the change of a magnetic
4:31 field we get a step down output because
4:33 of our secondary coil so we look at the
4:36 data sheet of this device and this is
4:39 actually just the the component itself
4:40 the current Transformer you may be
4:43 wondering well what is that electronic
4:45 component that was there I saw way more
4:46 components than that well if you look
4:48 over here you see the directions for use
4:50 we actually see we have a off amp over
4:53 here and it's because it is as you know
4:54 no problem is the amplifier signal and
4:56 the current Transformer you're getting a
4:59 very minuscule signal it may not even be
5:01 readable by our ADC that of our choice
5:02 this can be just plugged in straight
5:04 into a microcontroller like so in this
5:06 diagram I'll put on screen and this
5:08 op-amp over here is just applying that
5:10 to read both like Max 3v3 signal
5:12 essentially so that's all that's all it
5:15 is it is literally just this sensor and
5:17 an op amp it's how a lot of similar
5:19 things work with dating small signals
5:22 it's it's quite surprising actually when
5:23 you come around to it so let's take
5:25 example for it and completely off topic
5:27 but it's like for example EMG muscle I
5:29 don't know Electro muscle or something I
5:31 don't know I'm not too sure um so what
5:32 it is it sticks on your muscle and then
5:34 bike flexing or Contracting your muscle
5:37 it generates a small output voltage from
5:39 that signal and the signal is just
5:40 Amplified and that's how you get a
5:42 reading on to what is actually happening
5:43 so you see a lot of these similarity
5:45 it'll be like with the more technical
5:46 difficult stuff you've seen a lot more
5:48 but this is just the basic concept of
5:50 how it is so another popular method is
5:52 this hall effect sensor here which we're
5:53 looking at the data sheet it tells us
5:55 tells us exactly what it is gives us a
5:58 bit about these features description and
6:01 nicely a tip typical application circuit
6:02 which is always very useful and
6:03 typically comes with these data sheets
6:05 as per usual it is similar to any other
6:07 IC do not treat this as well as like
6:09 something special always comes in as
6:11 like always time and time again they
6:12 want to make it as easy as possible for
6:14 them for you to integrate their stuff so
6:16 you can come back and buy more let's
6:17 take a little bit of a look at it and
6:19 see what's there see what we can derive
6:21 from this and from this we are going to
6:23 take a look at how do we determine
6:25 something is fit for our needs so I
6:28 think the first thing is first is before
6:29 it's range and everything Supply voltage
6:31 is it worth can we use this in our
6:33 system so even just look at the typical
6:36 applications is 3.3 or 5 volts and
6:38 bypass where there's 0.1 microfarad
6:40 capacitor and this is pretty standard
6:43 amongst the embedded system designs or
6:44 whatnot you're usually working with them
6:46 these low voltage ranges oh that seems
6:48 to be good of course we can find this in
6:50 our specification also here we are in
6:52 the common operating characteristics
6:54 three to five point five typical five
6:56 volts but if you can use 3.3 really
6:59 Supply current it is quite a bit so
7:01 maybe keeping your mind but I don't
7:02 suppose you are constantly measuring
7:04 this maybe every so often if you're
7:05 doing some measurement unless you're
7:07 having some feedback loop I don't know
7:08 what you're doing but if you have a
7:09 battery powered device maybe it is to
7:11 worth keeping mind especially very
7:13 important like portable ones and such so
7:15 we've got that out the way what else are
7:17 we looking for let's look at its offset
7:19 to see if it's something that's really
7:22 critical to us so this output voltage
7:25 here we see it may drift over time as
7:27 much as 25 millivolts but I don't think
7:28 that is that much in our case so we're
7:30 going to keep looking we see different
7:32 types of things so I'm guessing this is
7:34 the model so we have different things
7:37 here 105 150. I'm guessing it's the
7:38 different models that they provide and
7:40 whatever model you choose how this but
7:42 maybe take this 151 over here electrical
7:45 offset voltage this is the drift is
7:48 referred to Ideal VL equals 2.5 volts
7:51 and we can see at certain parameters and
7:52 test conditions that we can get if
7:54 you're working between the 25 degree
7:57 ambient temperature 25 to 125 maybe we
8:00 get a 14 millivolt offset and my minus 4
8:03 to 25 we get a 24 millivolt offset so
8:04 that is keep in mind how accurate you
8:06 want your system to be if it's just a
8:08 basic refrigerant measurements I don't
8:09 think it really matters that much of
8:10 course this is all depend on your
8:13 project so things to keep in mind so for
8:15 that even we're wondering well the range
8:18 what what can we even range like what
8:20 what can we measure so looking at this
8:22 I'm assuming the primary sampled current
8:24 is what we can actually measure we see
8:27 zero to 100 minus 100 to 100 so 0 to 50
8:29 is quite a bit it seems like do 80 and
8:32 DC so this is quite quite big actually
8:34 we could probably use it with Mains and
8:36 now we are looking for its voltage which
8:39 I assume would be just as equal as as
8:42 much and fully capable so it's not
8:44 really clear with these if you specially
8:45 don't really know what you're looking
8:46 for but here we find in the isolation
8:49 characteristics that we can see the
8:51 working voltage for basic isolation and
8:52 Direction test strike so these are the
8:54 subsano tests that they go through and
8:59 we see we get a 700 vrms 990 VDC or V
9:02 Peak VPK even on a quick Google search
9:04 you may be able to find something if you
9:07 are not too certain and it's so it's not
9:08 that confusing so quick Google search
9:10 you see someone else has done it says
9:12 magnetic interface that automatically is
9:14 isolated rated for voltages up to 700 V RMS
9:16 RMS
9:17 so as you can see it's quite a bit that
9:19 it can really take and of course there
9:21 are other parameters that you may be
9:22 interested but I think these will be the
9:24 main one the supply voltage what its
9:26 current measurement and voltage
9:29 measurement to drift or it's offset if
9:31 you will see what else you might need
9:33 and anything else I think quick Google
9:35 or what have not but this is just to get
9:36 you started what measurement techniques
9:38 are available to you when you are
9:40 exploring this topic now before we end
9:42 off the video I'd like to show you a bit
9:45 of a summary sheet so I have a bit of a
9:47 summary table here for your reference
9:49 really if you ever wanted to see and in
9:51 this table I'll briefly go over a few so
9:54 here are five methods of measuring
9:55 current there are shunt hall effect
9:58 current transfer Rogowski forgive me I'm
9:59 probably pronouncing that wrong zero
10:01 Flex so if the connection type the
10:03 current accuracy range drift in
10:05 isolation now the isolation one is when
10:08 we saw the the vrms value and it's
10:10 isolated because inside that IC there
10:12 was actually a hall effect on this was
10:14 not actually passing through it's
10:15 instead sensing it so that is why and
10:17 you can tell the isolation you can see
10:19 for the current Transformers passing
10:20 through something it's not directly
10:23 connected and but for the Sean one you
10:24 saw we had to pass it through something
10:25 and that's why it's there's no isolation
10:27 in between so there's something else you
10:28 need to keep in mind but between
10:30 choosing something for your projects I
10:32 would keep these few parameters in mind
10:34 to see what you are measuring and I hope
10:36 this table comes in helpful so please
10:38 pause the video take them take some
10:39 notes if you really have to take a
10:41 screenshot and hopefully this helps you
10:43 in this part of what you think and what
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