Hey there!
we tend to drive a specific bldc sensorless motor using two different algorithms.
both of them are based on zero crossing detection, a vey simple approach.
the algorithm one detects ZCs by analog comparators and of course their corresponsive interrupts to apply the next step of commutation.
the algorithm two detects ZCs using ADC and then comparing the BEMF to VBus/2.
here is my broblem. the max speed achieved by algo.1 differes from algo.2 while the applied duty cycle is the same(for both almost 100%)
how could it be possible? I know that the speed is related to duty cycle so I tought the max speed would be the same no matter which algo I used.
I would be grateful if you could help.