[Prev][Next][Index][Thread]

Re: MOTs Rule!


Your protect resistors may be running too hot because coeff. coupling is too
tight.  Reduce it and see what happens.

Dr. Resonance



-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
Date: Friday, March 03, 2000 8:24 PM
Subject: MOTs Rule!


>Original Poster: "Gregory R. Hunter" <ghunter-at-accucomm-dot-net>
>
>Fellow Coilers,
>
>I've just tested my twin MOT supply with dual voltage doublers on my 4" x
>24" coil.  The supply is based on two MOTs salvaged from discarded 900 Watt
>ovens.  I borrowed the idea for it from Finnish Coiler Marco Denicoli.  I
>normally run the coil with two 9KV/60ma neons.  I use a single static
>vacuum gap made of 1" copper pipe fittings (yes, beefy) and a .023uF MMC.
>Toroid is 3.5" x 14".  I had to close the gap a little to get reliable
>firing from the MOTs, so I'm guessing voltage is in the 8KVAC range.   I
>used no ballast--the MOTs go as hard as they want to.  I ran the vacuum
>cleaner motor on my gap at full throttle in hopes of quenching the higher
>current.
>
>Results were pretty satisfying.  The streamers aren't any longer than with
>the NST supply, but they are much thicker, brighter, more intense, and more
>chaotic. They look as hot as lightning bolts.  There also seem to be more
>of them.  The spark gap sounds different too--much lower in pitch--almost a
>mechanical grinding sound.  It gives me the creeps.  Best spark length is
>about 30" (to my strike rail), and rarely a single streamer may reach out
>36" or so.  This thing really wants a bigger tank cap & larger toroid.  I
>plan to remedy both very soon.
>
>Current is provided by a 230V, 20A window air conditioner outlet in my
>garage.  The unballasted MOTs run warm, the doubler diodes & caps run cool.
> Oddly enough, the only weak link seems to be my 100 Ohm, 55 Watt RF filter
>resistors.  They run hot as pistols!  I'll have to go up to 100 Watt
>resistors I guess.
>
>Right now it's just a crude lashup literally taped together on my work
>bench.  I'll package the MOT supply properly over the next few days with
>neat, soldered connections, safety gaps, etc.  I may even immerse the MOTs
>in oil to enhance cooling.  I can't wait to try some longer runs.
>
>Low budget coilers unite!  MOTs rule!
>
>Greg Hunter
>Cochran, GA
>
>