Re: MOT info

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Mike" <mike.marcum@xxxxxxxxxxxx>

I wouldn't worry about the difference cost wise between 30A and 60A draw. 
Assuming you run it for an hour a day at ~14 kW (plenty enough to 
annoy/scare the neighbors/police/swat team) over a month that's $84 vs. $42 
for ~7kW. I seriously doubt you'll actually run it that much before spark 
gaps need replaced, ears need a rest, etc. I think it's always easier to 
use inductive ballasting and cheaper. With caps you'd need lots of them in 
parallel to handle the 30-60A and you'd need lots of uF (about 100uF for 
around 25A limiting off the top of my head). I haven't actually tried this 
myself, but seems like the caps would heat up like resistive ballasting. I 
personnly would just use the hardware store ballast, (2) 500' rolls of 
10-12 awg for 26A limiting.

Mike
----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, December 22, 2004 1:55 PM
Subject: Re: MOT info


> Original poster: Rich Simpson <richcreations@xxxxxxxxx>
>
> [sorry if this shows up twice, I used the wrong email account]
>
> I have seen the circuit that uses two mots wired back to back, then a 
> center taped mot stack, and I have seen the circuit that grounds the 
> "center" mots, and disconnects HV lines from the cores on the outer ones. 
> and I have seen greg's 4 mot stack that uses caps for ballast. as well as 
> various variations
>
> which of these seems to be the best, for a 6 or 8 mot stack?
>
> what about ballasting, I would rather not pull 50amps, 20-30amps would be 
> ok (I have a 240v/60a circuit to use, but at $0.20 per kw, I would like to 
> limit the current draw. should I use caps as greg has done, or should I 
> wind an inductor  around some rebar or welding rods?
>
> -Rich
>
> On Dec 21, 2004, at 11:12 AM, Tesla list wrote:
>
> > Original poster: "Christoph Bohr" <cb@xxxxxxxxxxxxxxx>
> >
> > Hello Rich.
> >
> > I have build a 4 and a 6-MOT stack in the past and both
> > performed pretty well in respect to power handling capability.
> >
> > I have the MOT's under transformer oil which keeps them cold and
> > aids isolation. Though I did not disconnect the cores from the inner end of
> > the
> > secondary winding I had no problems with arcovers during normal operation.
> > I experienced a primary to core flashover in one of the outer MOT's once,
> > but this was after exessive voltage rise while not using a safety gap, or in
> > other words
> > this was my own fault.
> >
> > I did not remove the shunts but always wondered if I had better done that.
> > Maybe anyone else can advise on this.
> > Howerever, these things are powerfull and cheap to build, but can be a pita
> > to
> > carry around, but a pole-pig isn't a lightweight neither.
> >
> > regards
> >
> > Christoph