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HELP with flash quenching IGBT/MOSFET

K

KD

Jan 1, 1970
0
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.

http://optoelectronics.perkinelmer.com/content/ApplicationNotes/flashlightingappnote.pdf
(page 3)


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...
 
P

Phil Allison

Jan 1, 1970
0
"KD"
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.

http://optoelectronics.perkinelmer.com/content/ApplicationNotes/flashlightingappnote.pdf
(page 3)


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 that an IXFK48N50 at circa $75 each ??

Is my MOSFET rated correctly???

If not, what rated MOSFET should I use??


** A bigger one.

What's the difference between an IGBT and MOSFET?


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

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).


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

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?



** Everything.


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



.......... Phil
 
P

Phil Allison

Jan 1, 1970
0
"KD"


** Stop SHOUTING !!!


Plan on blowing a lot of fets up.

Or electrocuting yourself.

Or both.


......... Phil
 
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