How to test capacitor

how to test a capacitor with a multimeter

Hello,


I have a capacitor, 6800 mF, 63V, electrolytic type.

Anybody here knows how to test if it is still working or not?

regards,

bigjoe

how to test capacitors

Use ≈50Vdc (or smaller) power supply and a test resistor (for easy calculations 1kΩ should do). Charge this capacitor through resistor and measure time, then discharge this capacitor with this resistor and measure time again.
For voltage of >95% (or during discharging <5%) the time should be 4RC to 5RC ..
Attached are typical curves of cap charging and discharging ..
Regards,
IanP

how to test capacitor with multimeter

dont forget to test the esr of such big capacitor !
the capacity can be good but the capacitor unusable if the esr is to high !

how to test a capacitor with multimeter

Hi,

To check if it is working it is pretty easy. Just apply a voltage to it (near 63 V) and disconnect it form the voltage source WITHOUT turning the voltage source off (if you do this you will problably discharge your capacitor trough the source)

Then measure the voltage on the capacitor with a multimeter. It should be almost the same voltage you have applyed.

Now to check if you still can relly on your capacitor you should measure its leakage current. This parameter is a good indicator of capacitor´s life.

To measure leakage current, connect an amper-meter in series with your capacitor and apply its nomminal voltage (63 V). Count ONE minute and read the current in the circuit. It should be less than (0.001 * C * V + 3uA = 431 uA -> This formula you can find on manufacturer´s databooks). You will need a good multimeter to measure current in this magntiude, but....

Anyway, if you are doing a hobby project, and the capacitor retains charge, just plug it to a voltage source for 20 minutes at its rated voltage and it will be back for good !

Hope I could help.
mcoster

how to test capacitors with a multimeter

Hello,

Thank you for the infos.

I appreciate it much.


regards,

bigjoe

test capacitors multimeter

Plz measure the voltage across a capacitor

High voltage capacitors problems???

sir, please help me out .
I m using 3300/6600 pF 3kV CAPACITORS. the input vlg is spark type high voltage i/p.. how cum we knw that these caps still work in high vlg with same charge holding capacity?? Is ESR of cap's really matters..??