>pulse accumulator technique, switch duty cycle in pwm often

Ah, now it starts to make sense. but I still think that the integration
period will be larger and require a longer time constant, and Roman wanted
fast response ? In fact, to obtain the same ripple if the period of PWM is
M and the period of the pwm modulation of the pwm (now I named it) is N
which is necessarily K*~M (~M is M averaged) then the integrator will need
a time constant at least K times greater than for a direct pwm (in M)
approach.

It would be possible to obtain more fine divisions, but in the end they
would be as fine as a simple PWM with period K*M, and have the same low
frequency components to be filtered.

I think that Roman chose certain pairs of M/N that correspond to his
desired, fixed output values, and switches between them to change the
output voltage, not to increase accuracy. This is what I understood so
far. And that those pairs of M/N happened to match his desired PWM output
duty cycles best.

Peter

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