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Re: 942c20p1 caps
Original poster: Mike <megavolts61@xxxxxxxxx>
Hi all,
I've been doing a lil research on polypropylene caps recently
If you properly derate them they should last longer and not fail
over time. I see that the WIMA brand has datasheets showing that the
derating needs to be more that youd' think at RF frequencies. The
WIMA (which I would assume is very similar to CDE caps) derate all
their caps above 1600V down to 700VAC at 1000Hz and about half that
at typical TC frequencies.
I would think if one does not properly derate them the end up
looking like swiss chees and will likely begin to change capacitane
over time...before they fail. So in my book, one should derate them
to about 40% of the DC working voltage and account for the peak
voltage of one's transformer.
This might be more expensive to do, but perhaps in the long
run, it'll be cheaper.
Mike
With a 12/60 I always use 2 parallel strings with 16 caps in each
string ---
.018 uF, 32 kV pulse rating. Less stress on the caps --- will last
for many years under normal use.
11 will fail after some time has elapsed.
Dr. Resonance
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