Re: MOT life expectancy in a TC

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

Original poster: "Jason Johnson by way of Terry Fritz <twftesla-at-uswest-dot-net>" <hvjjohnson13-at-hotmail-dot-com>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 17, 2001 1:19 PM
Subject: MOT life expectancy in a TC


> Original poster: "sundog by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<sundog-at-timeship-dot-net>
>
>
>  Hi all,
>
>   After looking over a few pages and the archives on using MOTs for the
tank
> tranny (I'm referring to paired mots for 8kv or so), using doublers and
> whatnot.

I use two MOTs for 4800 volts. No doubler, no level shifter, no chokes or
protection. I have not had a single problem with these transformers while
running up to 6 foot (2 meters) of spark.. They are still just as happy as
when I put them in their oil bath several months ago. The capacitor on the
other hand...

>
>  You have to admit it's a really potent little tranny in a small space.
The
> voltage doublers bring them up to our "normal" voltage range, and their
> current makes them simply little monsters.  But how long do the last in
this
> useage?  How often do you MOT-o-philes burn up a MOT-based tank tranny?
How
> many MOT users run RSG's on their setup?

As soon as I become un-broke I am going to buy the materials for a RSG, so
far my airblast spark gap works well. All I have for airflow on the airblast
gap is 2.2 cfm -at- 35 psi, which isn't very much at all. A 90 psi compressor
would work really well, or anything larger than my air compressor for that
matter (it doesn't even have an air tank).

>
>   Once you get the powerarcing under control, a MOT seems to perform just
as
> well as a PT.  Aside from the difficulty of finding 2 matched MOTs, what
> other problems are there?

My MOTs are not matched. One is around 2500 volts the other 2300 volts. They
were just the two biggest MOTs I had at the time I built everything. I think
that after you get used to MOTs they are the best transformers you can find,
short of a pole pig. Also when you run with MOTs coils seem to be picky and
like to self destruct if not in proper tune. (alot of power going into those
racing sparks, alot of current in the caps too, shoot for a big secondary
and primary to keep surge impedance up and gap current low as suggested by
John Freau)

>
> Shad
> PS, the List seems oddly quiet this last week or so
>

Jason Johnson