HELP with flash quenching IGBT/MOSFET

Dec 19, 2005 3 Replies

Hey guys,



Need help in finding an appropriate MOSFET/IGBT to pulse my hi energy flash lamp.



I currently have a 100Ws rated flash lamp running at 330V / 1620uF (88Ws)



I'm want to do pre-flash followed by the main flash so I decided to use a MOSFET to drive the trigger transformer and pulse shapping directly.



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I've been using a MOSFET with ratings of 500V and 48A continuous/192A pulsed. However, these MOSFETS have been dying on me after around 100 flashes... I did a current test flash pulse on them and found that it drew about 70A peak with a pulse duration of around 15ms.



Is my MOSFET rated correctly???



If not, what rated MOSFET should I use??



What's the difference between an IGBT and MOSFET? I also used an IGBT (rated for 85A continuous ) in place of the MOSFET and it failed to trigger with a logic signal directly from the microcontroller (5V). I then tried to manually trigger the IGBT with a 7V source and it only flashed once - assumed I blew the IGBT... what am I doing wrong?



thanks...


"KD"

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** Is that an IXFK48N50 at circa $75 each ??

** A bigger one.

** Oh dear.........

** Oh deary me ........

** Everything.

( This reminds me of the story of Microfarad and Millihenry. )

......... Phil

YES

HOW MUCH BIGGER?

I KNOW... BUT CAN YOU USE THE SAME DRIVER CIRCUIT? ARE THEY INTER CHANGABLE?

YEAH I KNOW.... I PLAN TO USE OPTO-ISOLATORS...

"KD"

** Stop SHOUTING !!!

Plan on blowing a lot of fets up.

Or electrocuting yourself.

Or both.

........ Phil

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