MEXICOWANDERER wrote:
HEEHOSEEEFAT!
Fire the damned MOSFETS with an optocoupler if you have to. Unless of course some of you claim the existing circuitry cannot or is not compatible with an optocoupler. The object in my humble opinion is to lower junction temperature within the device and or raise the thermal operation temperature limit.
I have heard chokes resonate like the Bells of St. Mary's.
This should not be a difficult or overly complicated upgrade, the MOSFET I mentioned has a very forgiving gate.
The feedback loop must use a fairly high level of current through the BJT's base-emitter junction for the transistor to work - very low 8-40 beta range.
This means the loop would still need to see this level of current to operate properly, so a significant design change would be needed.
FET's are volatge controlled devices and BJT's are current controlled devices...
