General > General Technical Chat

How to determine the voltage rating of an unknown capacitor?

(1/11) > >>

(In)Sanity:
Short of reading the marked values on a capacitor does anyone know of a method to identify the rated voltage of a capacitor?   Let me also add short of blowing them up or catching them on fire.   Does some characteristic of the capacitor change close to it's rated voltage,  such as perhaps the leakage current, etc? 

Thanks,

Jeff

houdini:
You could measure the capacitance and the size and see what caps match up with that and they will also have the same or similar voltage rating.

smashedProton:
If they are scavenged, probe the circuit.  you can also look at surrounding caps.

else, use a really nice equivilant cap

(In)Sanity:
I actually have two reasons for wanting to figure out how to do this.   First I have hundreds if not thousands of "scavenged" caps as you mention.  Also I have thousands of brand new SMD caps that I have no idea what their voltage rating is.   So short of blowing them up I'm trying to figure out their safe working voltage.

Thanks,

Jeff

AndyC_772:
For many ceramic capacitors, the capacitance starts to fall off quite sharply as the dc bias is increased. Perhaps you could devise a circuit which measures capacitance with a gradually increasing dc bias on the cap under test until the capacitance falls by, say, 20%, or you chicken out - whichever happens first!

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod