northumber82
Member level 3
Hello, I have an audio amp (of my creation) with mosfets as outputs (precisely IRFP240 and 9240).
I used the first configuration of Vbe multiplier as bias regulator (A type), all perfect but the temperature increase rapidly and my amp passes from class B to class A absorbing so much current. Then I tried to use the D type (according to the image), but the temp increase and I have the same effect. Yes, I have already dissipated the heat. What I should do? Increase R3 resistor in D? Sorry if I'm not enough specific, but I do not know precisely which parameters to list. I did measurements with bench power supplies and spectrum analyzers.
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SOLVED MYSELF: higher resistor in pilot emitters, better thermal stability
I used the first configuration of Vbe multiplier as bias regulator (A type), all perfect but the temperature increase rapidly and my amp passes from class B to class A absorbing so much current. Then I tried to use the D type (according to the image), but the temp increase and I have the same effect. Yes, I have already dissipated the heat. What I should do? Increase R3 resistor in D? Sorry if I'm not enough specific, but I do not know precisely which parameters to list. I did measurements with bench power supplies and spectrum analyzers.
- - - Updated - - -
SOLVED MYSELF: higher resistor in pilot emitters, better thermal stability