ive been trying to figure this out for awhile, but with no success. I built a full bridge circuit for an induction heater using 4 irfp064n mosfets. When i turn on the power, but not the signal, everything seems fine: the mosfets dont conduct. when i do turn on the signal, however, the mosfets seem to work the way they should for about 5 seconds and then the signal displayed on the oscilloscope on the tank circuit stops. when i turn off the signal, the mosfets still seem to be conducting and start smoking in a matter of seconds if i dont turn off the power supply too. when i turn the supply back on, but not the signal, the mosfets still continue to conduct. I know mosfets dont work well with inductive currents, but thats why they have antiparallel diodes built in them. when i check the driver signal, it works fine. is there something i am missing? why wont it work?
236 KB Views: 93