The motor parameters are: 7 pairs of pole DC brushless motor, according to the current Hall Effect Sensors installation position and motor parameters, Holzer's phase difference should be 90 degrees.
The current test encountered problems:
(1) the electrical angle of the two positions is 90 degrees, but it is found that the stator (coil) has a great influence on the amplitude of its induction. One of them is even V1pp=400Mv.
(2) when we found debugging, beginning Holzer induction was normal (normal, but also the angle difference) after a period of operation, the voltage waveform is induced by the poor, the poor electrical angle sampling also deviated from 90 degree (before many chip well, running after a period of time, there is reproduction of this problem, irreversible)