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Re: Capacitor Testing

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

What you really want to do is measure the loss or dissipation of the
capacitor at your frequency of interest.  A function generator, good
voltmeter and some resistors can do this quite nicely... The challenge is in
measuring a fairly small "equivalent" resistance in the presence of the
capacitive reactance, so you might up making measurements where you need
better than 0.1% precision, which is tough...

But, in general, the approach is to put cap and resistor in series, apply
test signal, and measure voltages. Then, calculate away...

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, May 15, 2002 5:44 AM
Subject: Capacitor Testing

> Original poster: "Marry Krutsch by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>
> Hi All.
> Are there any "easy" methods of testing unknown caps for TC
> suitability?  Something like a high power function generator that could
> push a given amount of current through a capacitor.  Maybe amplify the
> output of a small generator with a couple of HV MOSFETs and an MOT or
> two?  Since crummy caps seem "attracted" to me, I'd like a way to test
> them without smoking up the neighborhood :-0.
> Is this worth the time of day, or am I just an idiot? ;-)  Comments
> appreciated.
> Winston K.
> PS- Can I measure how much energy a cap dissipates using a "normal"
> function generator, and an o' scope?