Re: OLTC Questions

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

Original poster: "Stephen Conner by way of Terry Fritz <teslalist-at-qwest-dot-net>" <steve-at-scopeboy-dot-com>

At 17:39 14/01/03 -0700, you wrote:
>Original poster: "Terry Fritz" <teslalist-at-qwest-dot-net>

(snip)

>I do hope to get the OLTC stuff written up better soon.  Most information 
>is at:
>
>http://hot-streamer-dot-com/temp/Off-LineTeslaCoils(OLTC).txt
>
>And in the files beginning with "OLTC" at:
>
>http://hot-streamer-dot-com/temp/


I had a look at some of the stuff. I like your multi-primary concept to get 
current sharing with multiple IGBTs. It looks very like the solid-state 
klystron modulator that Greg Leyh posted about before Christmas. The paper 
he wrote on paralleling IGBTs in pulse appications was enough to put me off 
ever trying it. I already have all the parts except the IGBTs so I ran the 
numbers on a small 100 watt 400bps OLTC, with DC resonant charging to 600V 
off the rectified line voltage (240V here)

If I can get the frequency down to about 75kHz then the peak primary 
current is about 400 amps, which I believe is just about doable with a 
single medium-large IGBT. I think the challenge would be getting such a 
small coil to resonate at 75kHz without a ridiculous size of topload.

Steve C.