P
Paul
Hi,
The following image that contains my circuit is simplified for this
post. It works, but the losses are ridiculous due to the diodes! The
pulsed current through the inductor is around 50 amps, and lasts only
for a few hundred microseconds at most. The inductance is very low.
As you know, a MOSFET's Vsd (back voltage) is ridiculously low, and
can't block much, hence the diode. Now I can place enough MOSFET's in-
parallel to achieve low on-resistance, and the capacitance is low
enough, but as far as placing diodes in-parallel it doesn't do much
good beyond a few diodes.
The circuit:
http://apgpro.com/i/photo3.gif
Anyhow, is there a better circuit for doing this? Perhaps a way of
replacing the diode with a MOSFET, but that doesn't provide a good
ground path for the gate signal. I've tried IGBT instead of MOSFETs,
but that didn't work well at all ... sorry, I forgot the reason. A
mechanical relay would work if they didn't switch so slow.
Any ideas would be greatly appreciated!
Thanks!
Paul
The following image that contains my circuit is simplified for this
post. It works, but the losses are ridiculous due to the diodes! The
pulsed current through the inductor is around 50 amps, and lasts only
for a few hundred microseconds at most. The inductance is very low.
As you know, a MOSFET's Vsd (back voltage) is ridiculously low, and
can't block much, hence the diode. Now I can place enough MOSFET's in-
parallel to achieve low on-resistance, and the capacitance is low
enough, but as far as placing diodes in-parallel it doesn't do much
good beyond a few diodes.
The circuit:
http://apgpro.com/i/photo3.gif
Anyhow, is there a better circuit for doing this? Perhaps a way of
replacing the diode with a MOSFET, but that doesn't provide a good
ground path for the gate signal. I've tried IGBT instead of MOSFETs,
but that didn't work well at all ... sorry, I forgot the reason. A
mechanical relay would work if they didn't switch so slow.
Any ideas would be greatly appreciated!
Thanks!
Paul