Re: MOT doubler

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

Original poster: tesla <tesla-at-paradise-dot-net.nz> 

Hi Chris

With an output L of the two series MOT's of around 6Hy each and an
equivalent O/P C of 0.43uF that system is very close to resonance at 50Hz.
Those approximate values resonate at 70Hz, I suspect over current in the
Caps is an issue not to mention the possibility of resonant voltage rise.

Very interested to see what others think.

Ted L in NZ
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, November 11, 2003 2:07 PM
Subject: MOT doubler


 > Original poster: "Mudford, Chris" <chris.mudford-at-agresearch.co.nz>
 >
 > Hi All
 >
 > I've been playing with a two seriesed MOT with voltage doubler
 > arrangement (0.86 uF mot cap in each HV leg, 2 series mot diodes between
 > legs), but, had it fail last night.  I had two electrodes placed a short
 > distance apart on the final output and ramped the variac up until an arc
 > formed, this did not occur for long (3-4 seconds) before something
 > failed.  Initially I thought that one of the caps had come in contact
 > with the frame of the MOT it is on the output of.  But, there are no arc
 > marks and in the MOV the MOT and case of the cap are common with the
 > oven chassis.  But, both my caps are shorted (0.4 ohms).
 >
 > Can anyone enlighten me as to what may have occurred?  Should I have had
 > some series resistance?  I thought I'd seen this arrangement used in a
 > jacobs ladder.
 >
 > Look forward to peoples replies, even if they are scalding my ignorance.
 > I'm finding the more I learn the less I know.
 >
 > Cheers, Chris (NZ).
 > ==========================================================
 >
 >
 >