Seems to work pretty stable -- start up, over frequency range, transients ect. The idea is to sense quiescent bias for feedback control when one MOSFET is off. that gets averaged for liner control.
Since already shown publicly no patent ability.
Have enough patents already -- they are a lot of work!
If someone uses this idea I will more than happy with that
Have enough patents already -- they are a lot of work!
If someone uses this idea I will more than happy with that
You need to run a FFT to measure low levels of distortion.
This board has several threads on class AB auto-bias. Yours is in the "slow" (relative to audio) category.
The difficulty with slow auto-bias is that overlap becomes hard to sense when the amplifier is delivering high dv/dt. I believe that is an intractable problem.
Fast class AB auto-bias works, and class A auto-bias works.
BTW, comparator X1 needs a reference voltage.
Ed
This board has several threads on class AB auto-bias. Yours is in the "slow" (relative to audio) category.
The difficulty with slow auto-bias is that overlap becomes hard to sense when the amplifier is delivering high dv/dt. I believe that is an intractable problem.
Fast class AB auto-bias works, and class A auto-bias works.
BTW, comparator X1 needs a reference voltage.
Ed
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Show that the bias current is correct with no signal and does not change with any applied signals.
Ed
Ed
Your circuit is working better than I expected. Its behavior is not the same for both transistors. It is erring in the direction of too much bias with a signal, which is the opposite of what happens with other approaches. Make sure that the circuit can handle very asymmetrical waveforms (1:1000) in both polarities.
Ed
Ed
The currents in the above chart is intentionally made different for the two transistors as dictated by the input signal , not the bias. Throwing rocks at it
Yes, there is some variability in bias but I checked distortion and it always good over range and high load still has very little bias dissipation
Yes, there is some variability in bias but I checked distortion and it always good over range and high load still has very little bias dissipation