Degrading a capacitor

[nicedwarf]

Hi,

I would like to increase the ESR of a capacitor to demonstrate performance of a normal/low ESR and high ESR.  I'd like to increase the ESR, but not completely destroy it.

Any suggestions?
Thanks!

[dannyf]

Put a serial resistor to it.

[2N3055]

Put a serial resistor to it.

+1. I'm glad I was not drinking water.

LOL , but I was.. 

[nicedwarf]

:-)  yes, for a few reasons adding a resistor in serial is not ideal in this case.

[Ian.M]

So tear down some dead SMPSUs or CCFLs and salvage the worst ESR capacitors you can find that haven't actually bulged or blown. 

[DimitriP]

So tear down some dead SMPSUs or CCFLs and salvage the worst ESR capacitors you can find that haven't actually bulged or blown.

Replacing the capacitor with a  bad one might not be ideal in this case either.....   

[stj]

freeze it with spray and watch the readings on a meter.
 

[ANTALIFE]

Call it mean names, i'm sure that will degrade it's spirit ;^)

[T3sl4co1l]

It would help if you told us which kind of capacitor it is............

If it's electrolytic, you can simply shoot freeze spray at it.  As it gets cold (below 0°C), ESR rises considerably.

If it's any other type, add the resistor...

(Or if you want to prank someone, put AC across it.  Old tech prank: put a 1uF 100V polarized electrolytic inside the equipment end of a power cable.  Like an IEC computer power cable, for instance.  When your colleague plugs it in, the capacitor wheezes rapidly, and frustration ensues... )

Tim

[fubar.gr]

I once degraded an electrolytic by applying current limited reverse polarity DC with the intention to increase its ESR

You can see it here: https://youtu.be/AYjnxdvsI1U?t=758

A reverse biased electrolytic behaves kinda like a short circuit so it will overheat rapidly and explode.

But in this video I am using a current limited power supply. By adjusting the current I can make the temperature rise in a controlled fashion, so the capacitor vents but doesn't explode.

But I overdid it and the capacitor ended up with an ESR of over 40 ohms.

Also note that this is a very high quality Panasonic FC cap. A cheap capacitor won't hold for that long.