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Esr capacitor tester

mrel

Jul 2, 2008
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Hello
Does Esr capacitor tester, test all different types of capacitors or just electrolytic capacitor?
mrel
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
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Pretty much just electrolytic.

The reason is that the tester requires the capacitance to be sufficient such that the test impulse does not significantly charge the capacitor. In practice this generally eliminates the testing of many non-electrolytic capacitors.

Having said that, there are ceramic caps with high enough capacitance to test (mlcc caps).
 

73's de Edd

Aug 21, 2015
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Sir mrel . . . . .

ALL types . . . . BUT . . . . ESR is mainly being a problem emcountered with electrolytics .
Particularly ones that are subjected to high frequency or pulse related handling along with a parallel potential to run warmer, just by virtue of those conditions.

What few high capacitance non electrolytic capacitors I do have, of which the highest I have would be a 22 ufd mylar dielectric unit @ 50 working volts . . . .and many-many of cascaded lower values.

I will measure them and use them as " GOLD STANDARDS " . . . . to see if any electrolytic can even approach their low ESR values.
You just have to test-test-test and TEST several units to get the idea of average expected ESR values.

Plus, don't get thrown off if you come up against a 10 ufd @ 450VDC, since its inherently going to have a higher ESR than you had been accustomed to finding at lower working voltages.

If you want to prove something to yourself, test a high value cap for its ESR value and then take a 10 ohm resistor in series with the same cap and retest again.
Taking a 270 ufd capacitor at 25VDC you would find yourself having a mere 60ufd or so, actually being the equivalent capacitance then functioning in your circuit.

73's de Edd
 
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