How to test capacitors

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=46801
Printed Date: May 14, 2025 at 4:30 AM

Topic: How to test capacitors

Posted By: ryanmc
Subject: How to test capacitors
Date Posted: January 03, 2005 at 6:49 PM

Is it possible to test a capacitor I am curious if im getting what I pay for

Replies:

Posted By: deocder
Date Posted: January 03, 2005 at 10:23 PM

It's not very easy to test the capacitance of a capacitor. There is a piece of test equipment that will test it but I havn't seen something like that since taking class in college.

As far as testing to see if it stores charge and releases it, you would need to set up an amperage test. It is not as simple as putting a test meter on either side. I think a voltage divider has to be incorporated and I cant remember how to do that off the top of my head.

Maybe someone else can chime in?

Posted By: customcarchris
Date Posted: January 03, 2005 at 10:38 PM

I just bought a new multimeter the other day where you plug the capacitor right into it and it will tell you that capacitance of it. This multimeter only cost like $30 and has a bunch of other useful features. I haven't tried the capacitor test yet, but I'm sure that would be one of the easiest methods.

Posted By: haemphyst
Date Posted: January 04, 2005 at 9:06 AM

Not likely. To test a 1F or larger cap, you need to find a capacitance meter that is rated for testing that value - a tall order. Pretty much all of your handheld cap meters will not got hat big. I have only ever seen one, and it was about 650 bucks. BTW, here is a capacitance meter, rated for .1F, and it is 1750 bucks!

The RC time contant is the easiest way. Here is how you figure it. Good luck - I am not interested in figuring it out (not that I couldn't - just don't WANT to)! Probably oughta just take the manufacturers word for it - I'm pretty sure they are going to give you (at least) CLOSE to what you paid for...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: kgerry
Date Posted: January 04, 2005 at 9:55 AM

some of the new Fluke meters give you a limited Capacitance scale... I use a B&K 530 capacitor tester here myself.... you can not only check value but gain and leakage.....

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Kevin Gerry
Certified Electronics Technician
MECP First Class Installer

Owner/Installer
Classic Car Audio
since 1979

Posted By: customcarchris
Date Posted: January 04, 2005 at 4:40 PM

Oh woops, I was confused on the capacitor you're talking about. I have just been working with capacitors that are small lately, like 10 and 100 uf, not the large ones. I wasn't even thinking about the capacitors used for stereo equipment. Sorry about the mis info!