RE: Voltage reversal

Hi Herwig:

Your diode proposal would keep the cap biased at the same polarity, 60
Hertz-wise, but it's the oscillations and voltage reversals at the primary
tank frequency, 200KHz or whatever, that takes it's toll on the caps.  The
diodes wouldn't help there.

Regards, Gary Lau
Waltham, MA USA

		Original Poster: "Herwig Roscher" <herwig.roscher-at-gmx.de> 

		Hello coilers!

		Prior to designing my own polycap, I wanted to buy one and
sent the spec to
		some companies. The main problem - besides the price of
course - was the
		100% voltage reversal, that shortens the expected life

		I wonder, whether the use of a HV bridge rectifier between
xformer and main
		gap would help, to keep the cap alive a little bit longer.
In each arm  of
		the rectifier one could use e.g. 3 HV diodes from microwave
ovens in
		series, each parallelled by a resistor and a small cap.
Another possibility
		would be diodes with an avalanche characteristic, which
require no
		parallelled components.

		One drawback could be a material migration in the main gap.

		Did somebody try this circuit?