Capacitor Ripple Current

[Geordie340]

I know I have done this in the past, but i just can't remember the best way to do it.

I need to measure the ripple current for a capacitor, could anybody tell me the best way of doing this.

Thanks

 

[Russlk]

Put a small resistor in series and measure the AC voltage across the resistor.

 

[Geordie340]

thanks, thats the way I was planning on doing it (at the frequency of the circuit it is being used in), i just wasn't sure if there was another way.

 

[stevez]

It would seem that if the load is resistive AND you know something about it then you could measure the ripple voltage then calculate the ripple current. Please understand that I am presenting my thoughts to see if others agree that it makes sense. I'll be doing this myself soon and it helps to run thoughts by others for comments. That's the great thing about a forum like this.

 

[Russlk]

Stevez, no, that only tells the ripple current thru the load. For example, if the capacitor internal resistance is .1 ohm and the ripple is .1 volt, the ripple current is 1 amp. That same ripple voltage across a 1K load is 100 microamp.