Re: Larger Starting Capacitor?

You have to use a high impedance range and the modern meters just
measure and auto range. Analog meters will do it not real measure
but pretend t=R*C and if the Resistor range is high enough then the C
will then give a time that the needle to climb to the full value.

Modern meters just don't cut it with the current source they use.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Life; NRA LOH & Endowment Member, Golden Eagle, Patriot"s Medal.
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John wrote:
"Martin H. Eastburn" wrote:
Remember the ohmmeter is for resistors and can be used as an simple test
on other parts.

Caps are the hardest since the meter shows if it is open or shorted or
very leaky.

It doesn't show if the cap has capacitance at all. If it is leaky
at voltage or when hot.



I have been using ohm meters fro measuring caps for many years. You can
get a good idea if the cap is good or not by doing a couple simple
tests. First understand that you are using the ohmmeter as a charging
instrument with the ohmmeter indicating the rate of current flow into
the cap. The first thing you do is short out the cap. Then hook up the
leads to the cap and watch the incication on the meter. The meter will
go up and then back to infinite. Its the timing or length of the time
it takes to charge the cap. that is proportional to the value of the
cap. Measure a good one and compare it to the unknown one. The second
test is to hold the leads on the cap and charge it to full capacity. Then take the leads off and wait a half minute and then put the leads
back on the terminals. If the meter goes up and then back down the cap
is leaky. Granted these tests are not like using a precision capacity
meter but they work for a general indication of good and bad caps.

John

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