All You Need To Know About Op Amps To Fix Stuff. Part One - How Op-Amps Work

hi guys welcome to learning electronics repair this video was sponsored by PCB way and I have some of their pcbs here this is one of the shared projects we found on PCB way so these are projects that people have designed uploaded to BCB way and as a thank you to the author or the Creator if you are I order any pcbs from this design which is just a one click to do then the author will get a 10% commission from that sale so these pcbs are from this guy M guy yeah that's how we pronounce it and these are dual opab test boards but also to be quite honest these are also great teaching AIDS so let me just show you these on PCB Way's website here we are at PCB way.com and I hope you can see straight away that PCB way have quite a lot of services so they manufacture pcbs they also have PCB assembly they will build your entire project for you they have what you can see here many many different options flexible pcbs rigid Flex aluminium all sorts of things like vs in pads and uh plated ha through and plated holes PCB way also have a special offer at the moment you can see here this is the Christmas big S so if you've not tried their service before or you just going to go back and try it again I know lot of you guys do that then they have some special offers at the moment so you can see we have discount vouchers depending on the value of your order so orders of $30 or more $5 off $59 or more $10 off and so on so they have some great offers at the moment typically a set of five pcbs like the ones I have here will cost cost you $5 plus around the same in shipping depending on where you live to Spain it's about $450 something like that so for around $10 you can get five pcbs but even better than that if you use the discount code in the description to this video and you are setting up a new account then you get $5 off your first order regardless of the amount so you can get five pcbs effective for just the cost of the postage on your first order the pcbs we're looking at today are these ones opamp test boards so this is a shared project we can click on this we can see the layout of the PCB description this links to a YouTube video on the author's Channel and some suggested values for components you put in if you want to try the board as a test board we can just take a quick look so you can see here the boards this guy is showing you how to use them so I will link this video in the description to this video again credit where credit is due and if you want to see what the original author has to say about these boards then you can watch this video it is in English so what we are going to do in this video is to have a look at opamps what are op amps how do they work specifically from the point of view of a repair technician there's lots of ways to learn about opamps if you design your own circuits there's quite a bit of mathematics involved in doing that and there are a lot of considerations different configurations but from the point of view of repair what we probably want to know is what configuration our op amp is in on a device we're trying to repair and what voltages to expect on the output given the voltages we have on the inputs that's probably what we want to to know because we're going to try to determine is the opamp faulty or not or is it giving the expected output for the inputs that we have the inputs may be incorrect but if the output is correct for those inputs chances are the opamp is fine so I've actually populated a couple of these boards I'll show you here is one I have populated using the suggested values from the author's video and from the PCB way website this is really set up so that we can test two op amps one against another this is great for example if you think you may have a defective opamp and you have another one of the same or if you think you may have some fake opamp and you want to compare it with a genuine one so we can perform quite a lot of tests on here which you'll have a look at a little bit later in the video I've just noticed I've missed off a couple of the capacitors these decoupling capacitors here these are just on the supply voltage rail so I will solder them on before we use this the other components I don't need to fit at the moment these are if we want to put a Lo on the output of the opamp but I'm not particularly interested in doing that right now and these links here these are just wire links so you can actually feed an AC signal in here through a capacitor which removes any DC component but an opamp itself is a DC and an AC amplifier so if we want to play around with this and learn we're going to use an aill script to see some waveforms on here I think in our case we actually want to see the DC levels okay the board's designed to use a plus and minus volt Supply but you can modify it to use a single voltage rail such as 9 volts and ground here's a second one I've kind of populated I know it looks a bit messy but this basically allows me to plug components in so we can fit different value resistors we can put a link and we can put a capacitor in there's probably a better way of doing this I just cut up some parts of IC socket basically to get the little connectors I need and this seems to work well so I can for example take a resistor any value I like to try and I can actually connect it here just just plug in and plug in yeah obviously you can do this on breadboard but to be quite honest this is like looking at a schematic at the same time as building the circuit so the opamp actually fits here but this shows you a schematic of the circuit you're building and I honestly believe that if you are learning about opamps these are ideal because it's much easier to visualize what you're doing like this and it is when you're putting the thing together on a piece of breadboard because on the breadboard you may think well which resistor is this which one was that one you might forget what you placed where so I think these are great little educational Aids on this one you can see I've just built this half of the circuit using one up amp I haven't populated most of this because I don't want to use at the moment obviously I could do so we can play around as well with different values on this and we can do some practical experiments yeah I mean that's the way to learn this stuff so what is an op amp well op amp is actually a shortened form of operational amplifier and operational doesn't mean it works this name comes from the use of these type of circuits in analog computers so before we had digital computers we had analog computers that were effectively doing mathematics in an analog fashion in other words like you know one VT times 10 volts is 10 volts so actually the voltage represents the value and although we don't use that type of circuitry anymore the name stayed but what an OP ampers really is a differential amplifier so this is the symbol for an up amp it has two inputs and one output this is the output and the inputs are marked with a plus and minus sign this doesn't mean the positive input and the negative input what it actually means is the [Music] noninverting input and the inverting input okay you can think of if you like is negative as a minus maybe get inverting from negative but that's what they are what it really means is that a positive voltage on here will give a positive voltage on the output and the negative voltage on here will give a positive Vol on the output so any signal you put into the non-inverting input will come out in the same polarity on the output anything you put into the inverted input will come out upside down basically so why do we call this a differential amplifier well that's because the output is an amplified version of the difference between the inputs so if you see a difference between the inputs for example this was 2 volts and this was 2.01 volts then the difference is 0.01 a volt this is 0.01 a volt more positive than this so the output will be positive because it's non-inverting and the voltage will depend on the amplification of the or pamp and the same the other way if this was 2 volts and this is 2.01 volts they the output will be negative .01 volts times the gain what's the gain of this op amp well an ideal up amp the gain is infinite infinity infinity does not exist we could say it doesn't really exist in op amps anyway but the gain is extremely high 100,000 times 200,000 a million 2 million something like that so what this means is that a very small difference and the voltage between the two inputs will cause a big difference on the output okay if the gain of our op amp is 200,000 okay and we put on here for example 1.0 volts and on here we put 1.01 of a volt okay what will the output be well it be positive because this is the higher and it be 01 that's the difference times 200,000 okay do a little bit with the maths and the decimal points and I think we'll find the output on it would be 2,000 volts or it would try but it can't why well the voltage doesn't come out of like thin air the gain the increase in voltage comes from somewhere and where it comes from is the other two connections on this opamp which I didn't draw because has power supplies it has a positive Supply and this has a negative Supply and the output voltage is limit by the supply voltage so the output can't go higher than the positive Supply or lower than the negative Supply so what happens in this case when we have 1.01 volts here and one volt here the output will go up as far as it can where can it go to the positive Supply ra so if there was plus 15 Vols on here and there was minus 15 Vols on here the output would go to 15 or near most opamps can't actually go all the way to the supply voltage they probably can go within a vault some ups are designed to get much closer than that but the voltage will go up as far as it can when it reaches the limit that is called saturation so the amplifier output can no longer go any higher so if you increase this voltage more here that can't increase anymore okay and that's saturation so that's what an op amp is now I think you can see from this that an op amp is not much use as an amplifier because the slightest difference in voltage here will cause it to saturate yeah so in this configuration we cannot use an opamp as an amplifier but what we can do is use as a comparator so what a compar comparative will do is compare the two input voltages okay plus minus let's put some voltages on our off amp so if we want comparator we want something that we want to compare with something yeah you can only compare two or more things you can't compare one thing on its own yeah makes sense so as a comparator we have to put a voltage on this input converting input this is the reference this is the voltage we want to compare with let's give a good example just figures out my head we'll use a couple of 10K resistors this is a voltage divider we can have this connected to ground we can have this connected to plus 5 Vols for example and if you watch the video I made on voltage dividers you'll know because the resistors are the same value as each other the voltage on it will be 2.5 volts halfway and we can now compare that with something else okay so let's do something practical let's put another resistor in here I won't specify the value cuz we'd have to figure it out depending on this component and this component we're going to put a ldr light dependent resistor so this is a resistor that decreases in resistance as you shine the light on it okay you shine light on the resistance goes down you put into the darkness resistance goes up now if we know the ambient amount of light in it unlit room yeah I mean there's sunlight coming through the curtains but it's not L okay we can put a suitable value resistor or variable resistor here so that the input here is lower than this one okay what will the output be well if this is lower than this one even by a tiny amount the output will be the minus voltage rail you use 15 again so we'll have minus 15 on the output of our up amp now if somebody turn the light on this photos sensitive resistor would go down in resistance so the voltage at this point would go up above the 2.5 and then the output of here would go from minus to plus okay so this is a very practical example of why you would use this sort of circuit there's many other reasons and this is called a comparator and that is the most basic use of an opamp but I did mention that we would look at the operational amplifier from the point of view of repair and we will find this type of circuit and now we know how it works we know even with our multimeter to measure the voltage on the two inputs or measure the difference between them plus or minus and that will tell us what the output should be doing if the output's not doing that well we could have a 4y operational amplifier or for example we could have a supply voltage missing or we could have some sort of short circuit and whatever this is connected to that prevents it from changing the voltage but we would know there was a problem there yeah and an important thing I'll mention now so we discussed the fact that the amplifier doesn't create voltage the voltage comes from the supply rails that actually brings us to an important point about operational amplifiers and very much so in this circuit so point one the inputs on the operational amplifier are very high impedance and an ideal opamp they are of an infinite impedance that means that for all intents and purposes no current flows into or out of the inputs on an op amp they voltage sensitive but they don't draw any current so the main reason is that important well because no current flows in or out of here the voltage on here is directly a result of the proportion of these two resistors the op amp does not internally form another resistor like so in parallel with this one so the op amp does not affect the voltage that is applied to the inputs the same with this circuit so one input High impedance that's an important thing and as we go through a few more examples we look at the other most important things so the next common use of an op amp what happens if we take our op amp and we put a voltage on the non-inverted input one volt okay and we connect the output directly to the inverting input like that what'll happen what voltage will be on the output well the voltage on the output will depend on the difference between the voltage is on the inputs we know that okay so if we put one volt on here the output will try to go up to the supply R and the supply rail is on the example we had plus 15 minus 15 but when that goes up towards Supply rail it puts a voltage on the inverted input the voltage here goes up as well and if the voltage here went above that this would tend to go down towards the minus 15 or straight down to minus5 but that would put this input lower than this one so it would have to go up so you might think it'll oscillate but it won't oscillate what will happen is that when the voltage on the inverting input matches the voltage on the non-inverting input so in other words one volt on here that will balance okay and the output well it's connected directly to there so it must be one volt so you can see that if we connect like this we get an output that is the same as the input and if the input increases to say 2 volts the output will go up to 2 2 volts so this input will go up to 2 volts and it will balance again so that's what the circuit will do now this is called negative feedback okay we're taking the output and we're feeding it back to the inverting input okay okay so what we've actually created here is an amplifier with a gain of one yeah whatever go Zen comes out it's the same voltage so what's the use of this circuit has it got any use other than just an interesting explanation of our pamps well it has got a use it's called a Buffy and the reason it's got a use is because we know the input of the op amp has no current flowing into it it's a high impedance no current flows in therefore if this is connected to something like a microcontroller or something like that it's not drawing any current from the microcontrol it's just effectively monitoring the voltage on here yeah but the output of the opam has a very low impedance ideally the input impedance is infinite and the output impedance is zero of course nothing is ever ideal but it'll be close to that so it's has a very low output resistance which means that this can now Drive some load okay connected to Here Without drawing any power from the device that's controlling the input and that's a bu it so this tells us two more important things number two the output of the opamp is low impedance Z the symbol for impedance by the way it's not Russian okay and the uh second important thing which of course is the third one is that the op ample always try to balance the voltage on the two inputs if it can when cage well when this voltage here saturates it can't go anymore and it still hasn't balanced the input yet okay and we'll talk about that in a moment but number three is that the op amp will always try to [Music] balance the input voltages Proviso when it has a feedback circuit because the opamp itself can't alter its own input voltage but it can't alter its output voltage and it can use the output voltage or a proportion of the output voltage this is important to control the input voltage okay so those three things really are the only really important things that you need to know about op amps especially when you're trying to repair stuff because when you're trying to fix this you're not trying to design the circuit to operate in a certain way you're trying to test the circuit to see if it works as expected and what's expected well it's just the relationship between the two inputs to give a certain output so you don't really need to know everything that's connected around this to know if that pamp is working or isn't working as it should I just mentioned that with the feedback the circuit feeds back the output voltage or a proportion of it to the input so let's have a look at that we'll just change the circuit a little bit not much at all we have our up amp again out we have our non-inverting and inverting in inputs okay we have some signal coming in here and we take the output and instead of connecting it directly to the input we'll connect it to a resistor okay and that resistor will connect to the input and it will connect to another resistor to ground again like we saw in this [Music] comparator a voltage divider this is also a voltage divider it just looks a little bit different but it's a voltage divider but this voltage divider is connected between the supply voltage and ground this one is connected between the output of the up and ground okay so what it means is that a proportion of the output voltage will appear on the inverted input if the resistors are the same value say 10K and 10K we should know because a voltage divider the voltage here will be half of the output voltage V out over two half of it yeah that also means that for a given voltage here so this is one volt to get one volt on here this has to be two volt so this is called a non inverting spell it right amplifier and the gain of the amplifier is solely determined by the ratio of these two resistors it's a very easy formula for this we'll call this one a uh V FB voltage feedback okay and what's the formula well a good point to actually change the name of this to R feedback rather than V feedback okay and this we can just SC all one if you like so the formula to work out the gain of this amplifier it equals resistor feedback okay divided by R1 plus one why is it plus one well look back at this circuit so in this circuit the output was connected directly to the input so the feedback resistor was Zero okay there wasn't a resistor to ground so that was infinite or one so zero divided by infinite is zero basically semantics of mathematics if you like but it's zero so we can see the actual gain of this amplifier we already know is one one volt in to one Vol out so the gain is one so when we start putting resistors in to change the game with the feedback we have to add the one the amplifier itself directly connect has already got a gain of one so it's the ratio of these two resistors plus one okay what's that come to well that one there is 10K / 10K 10,000 ID 10,000 is 1 + 1 = two and that's why we got two volts on the output and by changing the values of these resistors we can ass set the gain of the amplifier so again if you're doing repair work and you you can see this sort of setup you know you have a non-inverting amplifier you know that the output will be in Phase with the input so the higher the voltage here the higher the voltage here until it saturates the lower the voltage here the lower the voltage on the output until it saturates and by taking the value of these two resistors simple formula you can work out what the gain should be so you can easily measure me the voltage on here measure the voltage on the output and you should be able to tell whether you've got the correct amount of gain okay there's another common configuration and that's an inverting amplifier so let's take a look at that one and this is quite interesting so again we have our opamp out minus plus you've noticed actually I guess I've drawn this the other way up so I put the inverting input at the top that's just to make the circuit easier to draw and understand really easy to visualize this is actually a fact so with an operational amplify on a schematic you will see it in various directions and like this plus minus minus plus you'll see them pointing that way and even downwards and upwards it just depends on how the layout of the schematic is and what makes it easier to visualize so these can be various Ways by the way so back to our inverting amplifier again we have feedback negative feedback here okay and we have an input resistor on this so the circuit is slightly different the non-inverting input well that connects to ground okay so let's have a look what happens with this circuit and we can apply the same rules we've learned so or FB just a feedback uh R in we'll call this could call it anything but R in why not okay so what happens here well imagine we have a signal coming in AC or this could be a DC voltage as the signal or voltage goes negative the output will go positive because this is an inverting amplifier and part of the output is being fed back to the input okay what's the voltage here well you might say the voltage here depends on the voltage of the signal you whatever's coming in and the ratio of these resistors if you like well that's actually not the case what was rule number three uh an opamp will always try to balance the voltage on both inputs so when the signal coming in goes negative the signal coming out goes positive it's inverted and the opamp will feed back enough of that signal to get the voltage on here to match the voltage on here what's the voltage on here well it's zero volts because this is ground okay as the voltage on the input goes more positive the output will go negative and it'll go negative until it can balance the voltage here with the non-inverting input which is zero so what actually happens is with this amplifier circuit if we look at the signal here we will see a signal going in or a voltage level okay if you look at the signal here this will always be zero volts the signals disappeared where is it well the only reason this is zero volts is because the output voltage is changing sufficiently to feed enough signal back here to balance it as I said many times so the output will have a signal now it will be inverted so if our input signal is like so our output signal will be like so Amplified by a factor which depends on the value of these two resistors the formula for working out the gain is slightly different to this one it is R feedback divided by r n and that's it so in the same example if this was 10K and this was 10K then 10,000 ided by 10,000 would equal one so the gain would be one the higher we make this resistor the higher the gain so for example if this is 20K then the formula now is 20K over 10K the gain is 2 so the higher this resistor compared to that one the higher the gain this can confuse people because if you're a fault finding you may go on to the input of this op up and say okay well this is zero it's ground yeah and there's a signal here so where's a signal there must be something wrong with the opamp no if the opamp is in this configuration which is an inverting amplifier that's exactly what will happen and on the output we will see the ampli signal so those are the main configurations which we find our opamp used in either a comparator a buffer a non-inverting amplifier or an inverting amplifier there's a few things we can note one is that the gain can be less than one okay so you can have a gain of .5 which you may say is not an amplifier it's anything it is a reducer yeah an attenuator that's the way attenuator but yes the gain can be less than one you'll also find operational amplifiers with capacitors in the feedback Network the capacitors are there to alter the gain versus frequency so it will have different gains at different frequencies the reason for that is because a capacitor passes AC and depending on the frequency of the AC it has more or less impedance impedance is like resistance it's just a resistance at a given frequency so you can see that by putting capacitors in these circuits you can make operational amplifier circuits that for example boost the high frequencies and cut the low frequencies think of tone controls for example on audio circuits so that's one thing you will find but it doesn't change the overall description of what the amplifier C is do and it's still one of these it just has a amplification that varies depend on the frequency you can also effectively daisy chain amplifier circuit so you could have the first one for example with capacitors in which would reduce the amount of Base the next one would then reduce the amount of treble above a certain frequency and coming out would just be the middle frequencies okay so things like that I won't go into these on this description because the test we're going to make on our opamps or DC voltage we may do something with AC signals but we won't go into this business of different response to different frequencies that's another topic yeah just be aware that you will find that in these sort of circuits we can also use opamps to for example oscillate we can make oscillators with opamps that oscillate at a certain frequency we can make circuits that will for example give a time delay between a pulse on the input a pulse on the output we can make circuits that will give a set width of output pulse for a given change or when the voltage on the input changes we get a single output pulse there's many things we can do I'll give you one example because this is something you're familiar with this is a comparator circuit we know it's a comparator if we feed in on the non-inverting input a sort tooth wave yeah that's a wave form like this and on the other input we put a voltage yeah a DC voltage and draw it like this what will happen well we know about a comparator so you can see that when the sore tooth goes above the voltage on this input the output will go high okay so we can see if we just draw this this is the input this is the output so the output will go high and when the sth goes below that voltage the output will go low and the same thing will happen when it goes above that voltage again the output will go high when it comes down go low I think you can see now what happens if we change this voltage what if we put it up here well look we still got the same thing happening so when the Sawtooth goes above our voltage which is now here the output goes high and it stays High Till the Sawtooth comes down yeah and the same on the next one okay do you see what we've got there it's a pulse with modulator yeah if that voltage is your feedback circuit monitoring the output of the power supply as the output of the power supply goes up the feedback voltage goes up it's higher up this Sawtooth wave that's fixed and we get a narrower pulse less output yeah that is a pulse with modulator so I hope you can see that op amps can be used in many many ways op amps can come in various packages usually they are in a 8 Pin or 14 pin I see package these are through hole ones we also get surface mount ones as well these are are a very common up amp the ua741 this is a single up amp in one package we can get similar packages with more than one up amp so for example these lm358 These are in an 8 Pin package again these have two up amps independent up amps in the package and we can have chips with four in such as this one common quad upamp so this has four individual opamps in one package the power plus and minus are common to all four up amps but the up amps themselves inputs and outputs are independent so you can use one two three or four of the opamps in here in your circuits really this is just to make the circuit smaller by using one package for example with four op amps we even have devices like this one as15 this is commonly used to drive LCD displays TFT displays for monitors and TVs this effectively sets the color balance for each pixel on the screen and this contain you may guess from the name or the port number as15 it has 1550 off amps in here in fact we can see the pin out for the as15 here so you can see in there effectively are 15 opamps they're shown like buffers because they're used as buffers but they are actually each one an op amp in fact it tells us here railto rail up amps rail to rail means they can drive the voltage all the way to the minor Supply or ground or all the way to the P Supply you will sometimes find op amps in this sort of package a metal kind of looks like a top hat basically or rather a bow hat with lots of legs on these were use a lot in vintage equipment but you can still buy these sort of up amps advantages of these in particular are that they are screened so they less likely pick up interference so you may find op i'ms that look like that also another thing I'll mention with the opamp you see that on all the examples we've used here we have a plus and a minus Supply you'll also find opamps that are used with a single Supply voltage obviously not having a negative Supply voltage they can only handle positive giving signals so in things like audio amplifiers you will find the plus and minus the same applies for instrumentation amplifiers one reason for that is because the output of the opamp can't go all the way to zero normally whereas if you use a plus and a minus Supply as we put 50 and 15 the opamp can go to exactly zero it's halfway in between okay but you will find opamps in circuits use a single voltage Supply one of the common ways that is done is to actually put a voltage on the inverting input similar to how we've seen before with a voltage divider and set the voltage here to be half of the supply voltage and we can now effectively amplify AC signals here and the signal will go between zero or close to zero and close to supply voltage but it's still basically alternating it just doesn't alternate below zero that are opamps that are specifically designed to use in these type of circuits so you'll often see in data sheets an opamp that says it is for single rail circuits some opamps have extra pins on for things like offset and trimming is they called kind of like calibrating the opamp so the zero level is zero level and you may find other specialist op amps that have other signals as well but they'll still all have this basic principle they are an opamp and you can get power opamps so normally an upamp can handle maybe into the hundreds of milliamps if you find things like audio amplifier chips stereo amplifier chips Mono Amplifier chips motor drivers and these sort of things they often are op amps they just a type that can handle more power and drive more output but still the principle of operation is the same there are other factors as well that effectively determine the type of op amps that you can use in given circuits one of them is the frequency response so some op amps you can put signals into into the kertz OR hundreds of kilohertz some of them into the megaherz or even gigahertz so some op will have a much wider bandwidth than others some opamps have a higher stability so these are often used for instrumentation where you actually want to make accurate measurements of for example very low voltages and currents you need to amplify the volage current to measure it and therefore the gain of the op amp is critical to give you a calibrated instrument that gives you a correct reading so some answers specifically for instrumentation and there's another Factor this is really related to the frequency response and this is slow rate so as I mentioned with for example our comparative when the input on the non-inverting input goes higher than the inverting the output will go from the minus rail to the plus Rail and I shown that as a vertical transition but that's actually not always the case depending on the op amp it will always take a finite amount of time to get from there to there and how long it takes it's called the sow rate so not up with a slow SL rate will effectively give you a transition more like that and the higher the SL R the more like a square wave this becomes because we've been talking about repair this is a repair Channel you can have problems in circuits where the slew rate is too slow possibly due to some components around an op amp or the op amp itself but commonly because you've got a fake op amp so high slow rate up hamps are more expensive in low or slow slow rate and it is quite wiely if you're buying from China for specific types of sort after fast slew rate up amps you may be sold a remarked or rebadged one a low SL R okay so that is another thing that we should always consider when we're talking about repairing up and based circuits and here are our nice test boards from pcb.com you can see we have on here two non-inverting and two inverting amplifiers well we can actually use this board to test the other configurations as well if we leave this resistor here open circuit so we don't fit this resistor and we don't fit this one either so we've just got the inputs to the op amp we can actually use this to make a buffer one to one game buffer and if we connect from here the resistor to ground leave this one out and we connect from here another resistor to the supply rail yeah we can actually make a comparator using this so we can modify this to make comparator circuits or buffer circuits quite easily so these are the things we're going to experiment with we can also experiment by putting capacitors in the feedback Network as well we'll do this in part two hey part one is far too long already some more say but I think there's a lot to cover here so I'll make part two sometime next week I want to give a few days for you guys to watch this video and comment because this is such a big topic there are about to be things that I didn't mention that I should have mentioned bear in mind this is primarily a repair Channel and this video is all you need to know about opamps to fix stuff so I don't feel myself as any need to go into any complex mathematics or design principles with this but you guys let me know what you think if you especially come up with some points regarding the repair side of opamp circuits something I've missed I'll almost certainly put that into part two the other thing on part two this is going to be pretty much all practical we've done the theory now so we can refer back to the theory we've done but this is going to be the Practical we're going to build each type of these circuits and we're going to test everything that we've described to prove if that's the case we can also compare some op apps of the same type see if we can find any fake ones and we can compare some up apps of different types to see if we can prove that one has a faster slew rate than the other these boards really are designed for dual rail operations that's what I'm going to do on the next video I'm not going to do any single rail stuff okay I hope you really did enjoy that one guys I've enjoyed making this I've promised it for quite some time so comments below let me know what you think and I will definitely see you all soon with part two of this one thanks for watching learn electronics repair sh for now guys

Channel: Learn Electronics Repair

Views: 12,146

Keywords: electronic repair, lessons, course, training, school, electronics repair, troubleshooting, fault finding, electronics, diagnosis, diagnosing, repair, multimeter, how to use, operation amplifier, how op amps work

Id: HY7NujELVoA

Length: 51min 32sec (3092 seconds)

Published: Thu Dec 14 2023