Re: MOT-powered coil questions

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

Original poster: "claude masetto by way of Terry Fritz <teslalist-at-qwest-dot-net>" <claudmas-at-optusnet-dot-com.au>

Hi Steve, have you got a diagram of your D.C MOT power supply and charging
choke.
Claude.
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, May 29, 2003 11:46 PM
Subject: Re: MOT-powered coil questions


 > Original poster: "Stephen Conner by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>
 >
 > At 19:12 28/05/03 -0600, you wrote:
 > >Original poster: "Gregory Hunter by way of Terry Fritz
 > ><teslalist-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>
 > >
 > >Quenching a low voltage/high current arc presents
 > >difficult design challenges that most newbies would do
 > >better to avoid. Raising the voltage a bit with a
 > >level shifter, or by simply using 4 MOTs instead of 2,
 > >sidesteps many problems and greatly simplifies spark
 > >gap design.
 >
 > I do tend to agree. A great way I've found of using MOTs is to use a
 > voltage doubler circuit (a Greinacher doubler for all you HV weenies) that
 > produces a filtered DC output. Two of these doublers wired to a single MOT
 > will produce +/-5kV ie 10kV in total at around 80mA. Of course being a DC
 > coil you need a charging choke and a rotary gap. But the high voltage and
 > high inductance of the choke make quenching easy so the spark gap design
is
 > a no-brainer. I used a vacuum cleaner motor and brass screws for
 > electrodes. Also the choke is easy to make from several off-the-shelf
 > chokes in series, and you don't need any other kind of ballast. The
 > downside is that you need to collect lots of MO caps and rectifiers, by
 > which time you would have got at least 4 MOTs anyway |-6
 >
 > My fellow countryman Dave Gamble has a similar DC coil but with two MOTs
in
 > series to produce a total of 20kV DC. His charging chokes were made from a
 > couple more MOTs with the 'I' part of the core sawn off. He gets up to 7'.
 >
 > Steve C.
 >
 >
 >
 >