MOT Tripler

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "S & J Young by way of Terry Fritz <twftesla-at-qwest-dot-net>" <youngs-at-konnections-dot-net>

List (especially the DC gang),

My dual MOT plus voltage doubler DC power supply produced about 9 KV (plus
and minus 4.5 KV) under load.  This required setting RSG gaps very close
which I don't like to do.  My RSG is driven by an el-cheapo Harbor Freight
angle grinder, and there is some bearing slop which causes my heart rate to
go up with higher rpms - scarey!

So I converted my two voltage doublers to triplers.  This works very well,
producing over 13 KV under load.  The caps in the first two stages of the
circuit are only 1 Mfd microwave oven caps, so the output is a bit droopy
under load.  The final stage of each tripler uses two 23 Mfd 4.1 KV caps in
series to act as a stiffer reservoir for the TC.

At a RSG break rate of about 500 BPS, spark length with the dual MOT doubler
was 30 inches with 611 DC watts.  With the triplers spark length increased
to 42 inches (1440 watts) at the same break rate.

My triplers use 3 MOT diodes which so far are holding up well.  I do feed
the resorvoir caps through a 750 ohm power resistor to protect the diodes
from current spikes.

A good practical resource for designing DC power supplies is the radio
amateur's handbook.  Used copies sometimes show up on E-bay.  the handbook
has circuits and theory for doublers, triplers and quadruplers.

--Steve