RetiredHAL
New Member
Just a quick question. What quick method is used to check for open or shorted capacitors. Indication only for short or open. I am not after a capacitance reading. I am restoring an old radio. Most caps after 50- 60 years have some leakage. I use an Analogue (moving coil meter, 15 v battery for X1000 Ohm Scale) to check.
An electrolytic will usually show a dip and then slowly climb to Mohms.
I tried to check some .1mF --- .oo1 mF (not electrolytic) and the meter did not dip at all. (indicate open) So I used an extra resistance 4 Mohm in series with the cap under test. Still no dip. I thought that with the extra series resistor I would have seen a small charging effect resulting in a small dip. eg 4M x .1mF = .4 CR sec. NB I have not checked this method with known good caps, I will tomorrow.
cheers RH
An electrolytic will usually show a dip and then slowly climb to Mohms.
I tried to check some .1mF --- .oo1 mF (not electrolytic) and the meter did not dip at all. (indicate open) So I used an extra resistance 4 Mohm in series with the cap under test. Still no dip. I thought that with the extra series resistor I would have seen a small charging effect resulting in a small dip. eg 4M x .1mF = .4 CR sec. NB I have not checked this method with known good caps, I will tomorrow.
cheers RH