The 1500uf cap looks like a direct short to the FWB for a good number of cycles.
One other possible way is to step the voltage up from the bridge to the
"isolated" mains by temporarily injecting a resistor in series with the mains
and the FWB and then shorting it.
Rick

Chris Loiacono wrote:

> I have put together a setup to PWM a 90V PM motor that uses an unregulated
> 170V supply from the AC line in a low-side switching arrangement. The supply
> consists of a 6A 400V FWB & a 1500uF cap. I wiped out a bridge when testing
> this and reasoned that perhaps back EMF, or perhaps a program glitch may
> have allowed a hard pulse to the MOSFET which would have made high inrush
> current...

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads