On Wed, 2009-11-25 at 13:28 -0800, Bob Blick wrote:
> On Wed, 25 Nov 2009 15:58:10 -0500, "Herbert Graf" <hkgraf@gmail.com>
> said:
> 
> > 
> > You know, that's a really good question... perhaps they have two "big
> > caps" and a switch that switches to the second cap after the first
> > flash?
> 
> That's what I was thinking. I could reuse the trigger and charge
> circuitry(plus a rectifier for each cap), and use the flip-flop to
> alternate the two caps.
> 
> I wonder how much current I need to plan for? It would be nice to use
> MOSFETs for the switches so I'm not burning up base drive on a
> bipolar/darlington, but 400V devices have pretty high Rds. I guess I'll
> have to try to measure the peak current (without getting shocked too
> many times). Thanks!

You could calculate. Check the rating on the cap in question, find the
typical flash duration and minimum voltage the flash will sustain the
arc and a little math should give you an idea.

TTYL

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