Patent ID: 9306479
Filing Date: 2016-04-05
CPC Classification: H02P

Claim Text:
1. A variable speed fan motor, comprising: a) a variable speed motor; and b) a motor controller, the motor controller comprising: a microprocessor, an inverter circuit, a signal detection circuit comprising a plurality of Hall current sensing units, and a DC power supply unit; wherein: the DC power supply unit is adapted to convert AC current into DC current and output the DC current; a first AC input end of the DC power supply unit is connected with a first power input line; the signal detection circuit is connected with a plurality of second power input lines; one of the second power input lines is selected to be powered on; the others are powered off; each of the second power input lines is connected with a first input end of one of the Hall current sensing units; second input ends of the Hall current sensing units are in parallel connection, and are connected with a second AC input end of the DC power supply unit; an output end of each Hall current sensing unit is connected with an input end of the microprocessor; the microprocessor is adapted to select operating parameters according to an energized signal of the second power input lines, and is adapted to control the variable speed motor to operate in accordance with the selected operating parameters; the DC power supply unit comprises an anti-electromagnetic interference circuit, a rectifier circuit, and a DC-DC transformation circuit; the anti-electromagnetic interference circuit, the rectifier circuit, and the DC-DC transformation circuit are sequentially connected in series; the first AC input end of the DC power supply unit and the second AC input end of the DC power supply unit are directly connected with the anti-electromagnetic interference circuit; and the DC-DC transformation circuit is adapted to output at least two DC voltages.