Which Capacitor Tester Should I Buy?

hi there and welcome to another episode of mr. Carlson's lab this video we're going to take a look at a whole bunch of different capacitor testers that will help you determine which particular capacitor tester or capacitor testers would be the best for what you're servicing there's many different tests that can be performed on capacitors and all of these testers test capacitors a little bit differently and I'll get into that in this video so let's get started the first capacitor tester that we're going to take a look at today is this Pako model C 25 and this is classified as an insurgent capacitor tester and it truly is an in circuit capacitor tester due to the ingenious little circuit that they've designed inside this box really is quite bizarre so there are two tubes inside this unit first is the indicator tube here and then there's a little oscillator tube that's located inside the power supply inside this box has no filter capacitor so both of these tubes are running off of AC there's no filtering at all very interesting design so it almost makes one of these capacitor testers pretty much ready just to plug right in and try out there's no filter capacitors to really go bad and damage anything inside the device very interesting now these particular capacitor testers can be had at you know ham radio swap meets or online for relatively cheap and when you get them it's always a good idea just to go through the many ways and you know check everything out make sure everything is good now inside this unit is a 40 megahertz oscillator and that 40 megahertz oscillator is basically feeding a signal through this piece of coax which is cut to exactly one quarter wavelength now there's a trimmer capacitor inside this that you can adjust so you know if it's trimmed a little shorter a little longer you can adjust that frequency in there the person that added these ends on to the end of the coax here obviously did not understand how this works because these are way too long and this is going to cause erroneous readings so these need to be very short little leads with little alligator clips on the in order for this thing to work correctly and I plan on doing a restoration on this little capacity tester here in the future so if you're interested in seeing that leave your comments below and I'll revisit this in the future so at any rate a very ingenious design so the whole idea is to complete a 40 megahertz signal through this piece of coax here and then what you do is you clip this into the circuit across the capacitor inside the circuit and whatever is hooked in line or you know if there's any resistors that are hooked to this inside the unit because this is oscillating at such a high frequency it's going to basically ignore the rest of the circuitry so when I get into the restoration of this particular device I'll explain a little bit more about that at that point now one of the the cons to this particular device is a lot of the capacitors that you're going to be looking at in say a radio and amplifier or say even an older television nowadays have developed leakage this particular capacitor tester is a go or no-go kind of test it's basically looking at extremes it's either a short or an open capacitor and that's basically all it's looking for it's a relatively easy tester to read because a closed eye indicates a defective capacitor in these modes here so this really is not going to indicate leakage and that's a very important thing to be looking for nowadays because the capacitors in these older amplifiers and you know radios and televisions are developing leakage by now because they're breaking down inside again this is looking for extremes this is either looking for a short or for an opening the capacitor so you're not going to be able to test that leakage that is the con to this particular capacitor tester this ICO 955 is very similar to the last capacitor tester that we looked at the difference being is this capacitor tester has a much reduced range if you recall the Pako went to 400 micro farad for testing electrolitic s-- this one tops out at only 50 micro farad now again this is an in circuit tester and it's not really looking at an in-between state it really is a go/no-go kind of test so we have a short test and we have an open test and then we have our capacity test here which we would use this for now in my own opinion if you saw something like this on a table unless you're an eco collector I wouldn't really be too interested in something like this now if you're interested in you know say that price was right say this was you know five bucks or something like that and the I tube and this was still good might be worth picking up for the I tube or if you want something just as a shelf queen or something like that you know that'd be fine as well so if you're interested in seeing the inside of this and going over the circuitry and seeing the way this particular device works you may also want to leave that below in the comments as well this unit oscillates at around 22 mega cycles whereas the Pako oscillates around 40 mega cycles so the design is similar frequencies are a little bit different things like that again you know this is really just the reduced range version of that other tester so in my own opinion you see one of these things and you're looking for a usable capacitor tester keep on walking Heathkit capacitor tester model Ct one similar to the last design yet even a further reduced range lower oscillating frequency about nineteen megacycles so again unless you're looking for a nice eye tube for an older radio or something like that my suggestion is to keep on walking this is one of my favorite capacitor checkers this is the heat camp model i t11 I have another favorite which is my Jackson model 591 but I won't talk about that today just because it pretty much does the same thing that this capacitor tester does is just a different name and in fact the Jackson is a little safer than this particular tester as well but that safety thing can be a catch-22 because the safety thing on the Jackson tester eliminates one of the functions that this particular tester is capable of and I'll explain that here in just a little bit so this is still a very valid piece of test gear today on any test bench this does a whole host of different functions and it does so many functions that it's really beyond the scope of this video here so explaining exactly everything that this tester does could be a video within itself now I really only use this particular capacitor tester for its leakage function you can see leakage here this is the test that all of those other capacitor testers didn't do those were all just pretty much go and no-go kind of tests this will test that in between state this will indicate when a capacitor is breaking down inside so on the paper is going back essentially the capacitor is turning into a resistor now this doesn't supply any RF into the circuit like the other capacitor testers do so this requires you to disconnect one end of the capacitor in order to make that test within the circuit what this does is this applies DC across the capacitor and reads the leakage current that the capacitor has itself so it'll measure the amount of leakage and it will display that on the eye here so if the eye closes that tells you that the capacitor is bad in that of course is when this is in the leakage position so this brings me to this safety talk about this particular capacitor tester this is a very dangerous capacitor tester if you don't know what you're doing just because of this switch right here now as you can see we have a voltage control here that goes from 3 volts in steps all the way up to 600 volts so if this is in the leakage position like it is now and this is up at 600 volts there is 600 volts across these two terminals at all times until you click this to discharge now you'll notice that this is spring-loaded in the jackson tester this is spring-loaded and it'll spring back to the discharge position this you can leave in leakage and forget about it and that makes this very dangerous now here's the thing many people want this non spring-loaded switch because they like to use to try to reform capacitors so there's that catch-22 thing so you need to be very careful with this capacitor tester if you forget about this and try to remove a capacitor you're in for a nasty shock if you have an electrolytic capacitor across these terminals it could be deadly so you always need to remember to click this to discharge watch the tube up here the tube will indicate when the capacitor is discharged once this indicates the cap is discharged you never take a chance you always take a screwdriver and short it across the capacitor before you remove it you can imagine what would happen if you have this in the electrolytic position and say you had a 100 microfarad electrolytic capacitor charged up to 400 volts and it wasn't you know properly discharged so say it was still again sitting at that 400 volts that would be a very very dangerous situation so if you're going to use a capacitor tester like this I strongly suggest that you read the instruction manual become very familiar with this device what I always do I always make a note to make sure this isn't discharge and turn that rate back down to three before I use it again for the next capacitor it's kind of like one of those things that you just do automatically if you were to forget and you left this at 150 volts and say you took a 25 volt capacitor and put it across these terminals and accidentally hit leakage the things going to explode so it can be very dangerous so you need to be very very careful with this capacitor tester so other than that this thing is a great device to use this has so many different features you can even look at turns ratios or workout turns ratios of transformers with this thing again this goes well beyond the scope of this video here again I only use this device for its leakage test I use digital meters for everything else and in a moment we'll take a look at those digital meters as well the next meter we're going to take a look at is known as an LCR meter so L for inductance C for capacitance and all are for resistance this particular meter has the added bonus of being able to test microwave diodes and Zener diodes at the six point eight volts the reason it will test the six point eight volts entered out is because the unit itself is powered by an internal 9-volt battery now the reason that I'm talking about LCR and not just see in this particular meter here is because if you're going to have any type of electronic service bench or if you need to do any type of electronic servicing there's going to be a point in time when you're going to need to test some form of inductor and this will do it the price of an LCR meter an LCR meter like this really isn't that much more than a dedicated capacitance meter and by having this you know you get all of this and basically one meter so very handy thing to have on the bench now the thing that really made this particular meter shine for me the dalm 240 this is made by circuit test is the inductance range this goes to 200 Henry's now on dealing a lot with modified heisting modulation and modulation reactors and a lot of the times those reactors are up around 60 to 80 Henry's and that exceeds the range of a lot of these particular types of meters this one here will test up to 200 Henry's so this is comfortably within their range that's what really made this particular meter stand out to me so you can test things with the alligator clips or you can plug capacitors directly into the unit itself to do the test so it is very versatile so this particular meter or some variant of a meter like this is an absolute must for any electronic service vention a letís if you plan on working on switch mode power supplies owning an ESR meter is an absolute must is our stands for equivalent series resistance so you can picture an electrolytic capacitor with a resistor in series with one of the legs now the nice thing about these particular meters is they will test a lot of the capacitors right in circuits so you don't even need to remove them again this is dealing with our RF so we're dealing with a signal at the jacks here which a lot of the times not all the times but a lot of the times pretty much avoids all the rest of the circuitry and there's you're pretty much just testing the cap now ESR you can look at it like this switch mode power supplies first of all are very hard on electrolytic capacitors a lot of the times electrolytic capacitors leak and I'll end up drying up when they dry up they develop ESR and ESR can be looked at like a resistor in line with one of the leads climbing in resistance over time as this is drying up well if we have a resistor say in line with a 1000 micro farad capacitor here and say it's up to 5 ohms and it's going up to 10 ohms and then up to 15 ohms well what's going to happen to that resistor if it's in series with that capacitor and the capacitor is working in the circuit that resistor is going to get hot and that's effectively what the capacitor is now doing it's becoming resistive and it's getting hot inside and it's kind of like a runaway situation the capacitor itself will keep getting hot and hot hot and really start to boil sometimes they burst out of the top and if you've worked on any kind of a computer power supply or motherboards you've seen that they actually kind of explode on the top and they let the pressure because they boil inside and that is because of developed ESR and that's what this particular meteor tests Tandi it has its own little chart right on the face right here so you can look up the rating of the capacitor and compare your ESR reading to what's on the chart here and you'll know if the capacitor is faulty or not again if you're working on any type of a switch mode power supply owning some form of an ESR meter is an absolute must to find these capacitors a lot of the times you'll test the capacitor in a normal capacitor tester just looking at its capacitance it'll test fine but when you test it with an ESR meter it grossly fails here's an example of using two different capacitor testers to help us identify whether a capacitor is good or bad the first test will be a capacitance test the second test will be a leakage test the capacitor we're going to test today is a brand new wax capacitor point one micro farad at 200 volts DC so as a wax on the leads here had to warm up the time machine this one so the capacitor tester here is set to 2 micro farad that's the scale it's set to because this capacitor is rated at point 1 micro farad so what I'll do is I'll just put the test leads onto the capacitor here and as you can see it's reading 0.14 so one might think that this capacitor is actually a little bit of an overachiever so it looks good on this tester now what I'm going to do is remove the two leads from this tester here and make sure the voltage is sitting at 3 volts and the switch here is on discharge I'm going to plug the leads in to the leakage test now I'll just set this off to the side so that I don't have to hold the capacitor when I'm putting voltage across this so now what I'm going to do is click the switch to leakage and slowly advance the voltage control here you keep an eye on the I tube you'll see that the I will close when I click this to leakage that's indicating that it's charging this capacitor when the capacitor is charged the I will open so here we go so there's 3 volts across this capacitor now the eye is open indicating that there is not excessive leakage current so we have 6 volts 10 volts 15 volts you can see it's slowing down 25 volts the eye is an opening anymore indicating that this capacitor is excessively leaky at 25 volts now if we look at the capacitor here again you can see that it's rated for 200 volts being a wax capacitor like this we know that this is going to be in some form of vacuum tube circuitry and chances are it's going to be close to 200 volts if this is leaking at 25 volts we're going to have a big problem with the equipment that this particular capacitor is in so this capacitor is very faulty so this did not indicate the fault where this did that's why it's so important to have a leakage tester let's test a small electrolytic capacitor so the capacitor we're going to test is rated 100 micro farad at 25 volts and as you can see it looks like it's in nice condition the vent hasn't popped or anything like that so the first test we're going to perform is a capacitance test so I'll take this capacitor and plug it into these slots right here and we have 104 micro farad capacitors rated at 100 micro farad looks pretty good now let's perform an ESR test so in order to use this little meter here what we need to do first is turn the meter on since this is a low ohms meter it wants to read its own lead resistance so we have to zero that out clip the leads together first and then hit the button one more time and it zeros that out so now we'll take this 100 micro farad 25 volt capacitor and test its ESR and as you can see we have 0.54 of an ohm so remember that point 5 4 if we take a look at the chart here we can see 100 micro farad at 25 volts the approximate worst ESR value is 0.32 this capacitor is reading point 5 4 which means that this capacitor has excessive ESR and needs to be replaced so you can see how important it is to perform multiple tests on many capacitors just doing a simple capacitance test much of the time is not enough thanks for stopping by the lab today hope you enjoyed this episode involving all of these capacitor testers if you did you can let me know by giving me a big thumbs up and hang around will be many more episodes coming like this in the near future if you haven't subscribed you may want to do that as well I also have an ongoing electronics course on patreon that covers vacuum tube and solid-state electronics and it's friendly to all skill levels so I'll have the link just below the video right about here if you're interested in taking part in that might want to check that out as well so until next time take care bye for now you

Channel: Mr Carlson's Lab

Views: 140,680

Rating: 4.955163 out of 5

Keywords: creativedesigncomponents.com, creative design components, Capacitor leakage test, esr, heathkit IT-11, Heathkit CT-1, paco C-25, dlm-240, wax capacitor, paper capacitor, foil capacitor

Id: lLQThhf3Brc

Length: 20min 44sec (1244 seconds)

Published: Tue Jun 20 2017