class d with multiple rails

[fredos]

Look for phase modulation amplifier, old patents from Peavey (DPC serie Power amplifier), work well, but hard to get ride of switching spike!

 

[Diymed]

Just cascode some slow high voltage high current mosfet with fast low voltage high current mosfet! Dont forget recovery diode! That work up to 6Kw with +/-280V rail. In each half leg of your bridge, you use low voltage as standard mosfet and with the 12-15V supply of the mosfet driver, you simply feed the gate of the high voltage mosfet. In that way, the switching device never ''see'' more than 10-13V. I doo it with SMD high current mosfet, without heat sink! Nearly all lose pass trough the cacoded high voltage fet and recovery diode.

hi all. mr fredos. i test cascode and cascoded device heat up and blow! i use stw45nm50 and irfz44 with mur1560 diode. for high side i use 15v floating from capacitor ir2110 and i use 10uf capacitor from gate stw45nm50 to source irfz44n.and 1n4148 from 15v to gate stw mosfet. sound is good self oscillated frequency fluctuate 150khz 300khz at idle and irz44 ir2110 blow. the circuit work well with irf640 irfp250 irfp260 irfb4227. but with cascode cascode device heat like krazy. i need your help please mr. i test with supply +50v -50v