Capacitors - checking large capacitors

PRESSON100

Member
Does anyone know where you can get a capacitor checker that can check the large 30,000 microfarad capacitors that we use in power supplies? I only see meters that can read up to 10,000 microfarads.
 
Look for a Sencore LC-53, Meter. .1pf to 199000uf range. 3-600vdc voltage test range for leakage. Also measures inductance. E Bay or test equipment outlets. Use one at work.
 
Look for a Sencore LC-53, Meter. .1pf to 199000uf range. 3-600vdc voltage test range for leakage. Also measures inductance. E Bay or test equipment outlets. Use one at work.
Looks good, kind of expensive. Maybe I can find a deal on ebay. Thanks.
 
There are not a lot of meters that can read up that far without going to pro type gear. The one at work has to be like 20 yrs old.
 
If you have a scope, you can measure ripple. Otherwise, if they haven't vented (started leaking electrolyte), aren't causing hum, or shorted, they are probably fine. Large can caps are very reliable components, and when they fail it usually isn't subtle.
 
I have what I believe is a clever method of checking these large caps. Connect speaker loads and inject 1KHz signal into the amp, monitor output with a scope. Increase signal to just below clipping. Then put the scope on the + and - main supply voltages to ground, and measure the 1KHz ripple. Less than 1V the cap is fine. Usually it's in the millivolts.
 
If you are electronically inclined, you can make a 555 chip timing circuit and the value of the capacitor will determine the timing interval. Because you can precisely measure the values of R1 and R2, the actual value of C can be calculated from the LED interval measured with a stopwatch.

astable-555-timer-led-flasher-circuit.png

http://www.555-timer-circuits.com/
 
Well, if you want cheap, are lacking a scope, are willing to forego the checking at different freq and other good things mentioned above, and are willing to wait a while for it to arrive, then there is this: http://www.audiokarma.org/forums/index.php?threads/cheap-component-tester.749729/

This link is more specific, at the vendor's page: https://m.banggood.com/DANIU-3_5inc...k2_9nvcm&utm_source=ShareASale&utm_medium=aff

I have ordered a few things from this vendor, and all came through and were as described. I am sure there are other sellers of this particular product as well, under different names, perhaps some are US located.

If you look at the specs, for capacitance it says "25pF-100mF". You might think it means 100 micorfarad (I did), but based on my experience with it, it seems it is 100 millifarad. I used it to measure some 47,000µF caps I had, and it took it longer than usual to report an answer (presumably took longer to charge it up), but it did report the right answer and the ESR. Might be good enough, depending what your needs and wants are. As always, YMMV, and I can't vouch for its accuracy, just reporting my experience.
 
I wonder, how would a cheap component tester having high contact losses due to bad clips or poor elcheapo fake textool sockets be able to measure the very low ESR of a big capacitor?

anyway my own elcheapo makes about 10% error on the capacitance area where it decides to switch measurement frequency.
 
Measured leakage at near/rated voltage can be informative, as well.
Can be considered important capabilities when looking for a more complete capacitor test set requirement.

But of course drives the price up ..

Over the years(actually decades ago(1991) I invested in a Sencore LC 102 capacitance/inductor tester, and though pricy at that time, it has paid for itself many, many times..
And I still use it occasionally for more thorough capacitor investigation, I find the Peak electronic design Atlas ESR+ ESR70 to give me inexpensive portable quick accurate information about capacitors..

It measures capacitance to 22,000 Mfd.
 
The cheap component testers are great for identifying semis and pin outs, but for capacitance they are poor. The reported ESR figures are complete rubbish.
 
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