Re: Voltage multiplier (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Sat, 25 Aug 2007 11:47:27 -0700
From: Ed Phillips <evp@xxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Voltage multiplier (fwd)

Is this the schematic you are asking about?

http://scopeboy.com/tesla/tc2schem.html

I'm puzzled.  Are you planning to use only his
multiplier circuit, or are you planning to use the
whole DC resonant charging circuit?

Doubling the cap size will greatly increase the output
current from the multiplier.  However, the power
throughput of the whole resonant charger is governed
by a number of factors, including load, break rate,
dwell time, etc. 

Let's consider just his multiplier section--without
the charging choke and de-Qing diode.  10kVDC @ 80mA
works out to 800W.  Since microwave ovens are usually
rated by cooking power, and since the magnetron is
roughly 65% efficient, this implies the MOT from
ScopeBoy's 850W oven may be capable of providing up to
1300W, or 10kVDC @ 130mA--a bit short of the 160mA you
are hoping for.  MOTs are built very cheaply, using
the bare-minimum core size and as few turns as
possible.  Translation:  don't try to push a MOT past
it's manufacturer's rating.  If you must have 10kVDC @
160mA, use a bigger MOT.

Cheers,

Greg"

	Your advice would seem to be appropriate for continuous operation which transformer heating due to core loss won't permit anyway.  Overloading by a somewhat higher current probably won't make any difference for short runs.

	Do you know if the guy at your link has run his coil yet?  The design looks sound.  I wonder if his charging chokes can take the voltage without core saturation but can't tell since he doesn't give primary capacitor values. I'd personally put the "de-Qing diode" [really a disconnect diode and the de-Qing doesn't mean anything in this application] on the other side of the chokes but since he has everything floating wouldn't make any difference.

Ed