Patent ID: 8860340
Filing Date: 2014-10-14
Classification: F04D,Y02B

Abstract:
1. A driving device for a multi-phase sensorless fan motor having a plurality of coils, comprising: a plurality of comparators, disposed for each of the coils, respectively, and configured to generate a back electromotive force sensing signal denoting a comparison result by comparing a back electromotive force appearing at one end of each corresponding coil with a neutral-point voltage of the coils; a forward/reverse rotation control portion, which receives a direction control signal used to assign a rotation direction of the fan motor in the normal operation to a first direction or a second direction opposite to the first direction, and outputs a signal to switch the rotation direction of the fan motor according to the direction control signal; a driving signal synthesis circuit, configured to generate a driving control signal used to drive the fan motor according to an output signal of the comparators and the output signal of the forward/reverse rotation control portion; and a driving circuit, for driving the fan motor according to the driving control signal, wherein the driving signal synthesis circuit comprises: