[Amps] Oil-caps delating 2/3 ratings?

Han Higasa higasa at plum.ocn.ne.jp
Fri Mar 7 05:15:52 EST 2008


Sorry not delating but derating.

I thank so much to those who gave me the answers on this thread.

As I did not find the information regarding these GE 4500V 32uF caps
except leakage from their body, I was wondering whether these caps
will work well in my HVPS.

Tangent delta means the ratio of its internal dissipation resistance Ro
and its impedance Zo produced by its capacitance.

My old bridge indicated the tangent delta of GE oil-caps about 
1.8% (at 1 kHz).  If the value is accurate and linear,

Ro = 1000000/(2*pi*100*32)  * 0.018 = 0.895 ohm at 100 Hz.

Comparing 16V 220uF chemical caps shown 80%, and 16V 10uF
around 61.5% I can say the 1.8% is an excellent value.

Additionally I am using all these oil-caps on a 1/3" glass epoxy 
board to avoid (an unusual) leakage from body to chassis.

Thanks to all, I have an opportunity to become aware of how 
I discriminate caps (fit for HVPS or not), and then measured 
tangent delta of these GE oil-caps and other chemical caps.
Now I am confident that I can use these oil-caps safely.

de Han JE1BMJ


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