Re: ISSTC questions

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Original poster: "Eastern Voltage Research Corporation" <dhmccauley-at-easternvoltageresearch-dot-com> 


Yeah, try different tuning points.  Every 1/8 turn and keep monitoring
output arcs.
I'm betting that your coil just isn't in tune yet.
As far as gate drive goes, you can push gates up to 30V to higher current
from the IGBT (i think Terry first suggested this)
but I get same results using 15V drive so it shouldn't make much difference.

Dan


 > Hi, I appreciate the suggestions. I am running on 190V max DC using
 > 5800uF electrolytic filter cap between the full wave bridge and the
 > Half-bridge. I think there are two things I am going to try; one, reduce
 > the number of primary turns to 5 (from 8), and two make the last turn
 > and a half tapable (is that a real word?). I need to find the actual
 > frequency with topload of my coil, will use my frequency meter or scope.
 > But calculate ~170-180 KHz. Then tune the tank in. We will see... Oh
 > yeah, I am also using a GDT with 16 turns 1:1:1, so I am only getting
 > +15V and -15V to the gates, so does it really improve performance to go
 > to 1:2:2 (+30V & -30V)? Or is that more for stability at high power? I
 > guess I don't really understand the idea of pushing the gate voltage up
 > so high.
 >
 > But must say I think worst problem I am having with this is with my Wife
 > ;-P
 > Will tell you, these guys are loud! And, of course, I have to try and
 > see just how shrill I can get this baby! I need those 20 acres in the
 > wilderness more than ever! Would help with some of my Pyro experiments
 > also ;-)
 >
 > Thanks for the input,