Re: Mini OLTC is getting 9"

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

Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dhmccauley-at-spacecatlighting-dot-com>

Very nice output pictures of your OLTC Steve.  Do you have any pictures of
your coil (close-ups) under normal lighting.  I'm curious to see what your
actual arrangement looks like.
Thanks

The Captain



 > Hi guys,
 >
 > I just got my mini Off-Line Tesla Coil finished. Now that it has a proper
 > power supply, it runs at 1200bps and produces 9" hot arcs to ground. It's
 > been an interesting project and kind of ties in with what Dan "Captain
 > Corona" McCauley was saying about the SSTC hybrid thing. Current is free
 > but you pay for voltage etc.
 >
 > The OLTC is kind of crippled by being restricted to about 700V primary
 > voltage. You need a very large tank cap to get a reasonable bang size, so
 > you have to use a one-turn primary and also a secondary with low resonant
 > frequency, which means the secondary is physically large, so it has lots
of
 > self-capacitance and therefore a low top voltage and poor streamer growth.
 > It also means the primary current is massive to the point that it isn't
 > free any more. My coil runs 900 amps peak and the IGBTs get pretty hot as
 > you would expect. They're probably about 60% efficient.
 >
 > I put some spark pics from the OLTC as well as a quicktime movie on my
website:
 >
 > http://www.scopeboy-dot-com/tesla/t3sparks.html
 >
 > Steve C.
 >
 >
 >
 >
 >
 >