Ripple Current Measurment

[tjalps]

0.1ohm ripple current

Hello!

Can anyone tell me how can I meassure ripple current on
electrolytic capacitors in power suply circuits?

Best regards!

 

[haymeron]

Hello!

Can anyone tell me how can I meassure ripple current on
electrolytic capacitors in power suply circuits?

Best regards!

********************************************************

hi.

use a current tansformer.
use a small toroied with high permability and low losses.
rewind 100 turns and connect a small resistor of 100 ohm 5%.

1A = 1V (100mA = 100mV)
connect to ch-1 in your scope and measure the current.

( if you dont have place for 100 turns, make 50 turns and use a 50 ohm resistor)

regards.

 

[Moss]

There is a simple way. You can connect resistor in series with capacitator. Of course resistor must have very small resistance - 0.1 Ohm for example. Even in case that current change ( ripple ) is about 0.1A you will see it with simple scope.

 

[jodokus]

The method of moss is simple but keep in mind that this only works in series with the ground lead of the capacitor and even then there are possible measure errors when ground is not the same ground as oscilloscope ground.
And if capacitor is not connected to ground it does not work at all.
use differential input of scope if available.

 

[sivakumar_tumma]

use CRO with ac coupling....