Re: Transformer build up

To: tesla-at-pupman-dot-com
Subject: Re: Transformer build up
From: Stefan.Binder-at-t-online.de (Stefan Binder) (by way of Terry Fritz <terryf-at-verinet-dot-com>)
Date: Sat, 19 Sep 1998 08:24:56 -0600
Approved: terryf-at-verinet-dot-com

Hi all!

> The real problem with a cascaded MOT scheme is the insulation for the
> second transformer in the cascade. (I assume here that you are hooking
> the primaries in parallel and the secondaries in series?) The core will
> be sitting at several kV, and the insulation from the primary to the
> core may not be designed to take that much load. You might check what
> the HiPot test voltage on a typical MOT is. It is probably in the few kV
> range, if they even HiPot test them (i'll bet they do, to meet UL or
> CSA). Then, for short impulses anyway, the insulation will hold up.
> 

Ok, here are the specifications of my MOTs

Rated primary voltage        230V
Rated frequency              50 Hz
Resonant capacitor           0.998uF
Raten oven power             600W
Insulation class             H         

No load wattage loss         80W Max
No load current              4A Max
No load sec. voltage         2020V +- 50V
No load filament voltage     3.3V +- 0.1V
Temperature rise             (Wire) 140 °C

Insulation resistance        100 Megaohms min 500V DC
Dielectric withstand voltage P-Core 1.5kV 1 min
                             F-Core 7.5kV 1 min
                             F-P    7.5kV 1 min

BTW I'm using my two MOTs with a voltage doubler, so I don't have to worry
about 
insulation voltage.

hope this helps,
 Stefan