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Re: Humongous SSTC (was SSTC hits 66" )



Original poster: jimmy hynes <chunkyboy86-at-yahoo-dot-com> 

 > go on rub it in :( :P But the switching losses for the big bricks _are_ bad,
 > I was looking at a datasheet for a 3.3kV 1200A unit, and the losses are
 > quoted in J, not the usual mJ.

Sorry :-( Even if it is a couple of joules to switch at 1200 amps, its 
still only a couple hundred
watts total, which has to be tiny when you're running a coil with 3.3kV 
1200A switches. If they're
actually switching at 1200A, then the peak current and energy transferred 
will be enormous :O

 > I'm also thinking I was too kind with the peak current in my OLTC stuff, I'm
 > going to double it and see what happens :)

Awesome!

 > This makes them cheap compared to the capacitor banks: one massive
 > electrolytic bank (something like 20000uF -at- 600v) and a large MMC. Caps are
 > harder to get surplus, because railgun and coilgun hobbyists buy up all the
 > electrolytics and Tesla coilers buy all the pulse ones.

That's why I said (in 4hv-dot-org) that the capacitors may be more important 
than the IGBTs in
determining the ideal topology. I don't think anyone has found out how hard 
the electrolytics can
be pushed yet...

 > I think the situation has changed though, thanks to our efforts in
 > popularising big SSTCs, Tesla coilers are now buying up all the surplus
 > CM600s too :(

Yeah... I have noticed that even though a bunch people are starting to 
build these SSTCs, even
more seem to have bricks :-/

=====
Jimmy