Patent ID: 8624535

Claim:
A power supply circuit comprising a first switching circuit, a second switching circuit, a controller and two terminals for connecting a motor, wherein each of the two switching circuits comprises a first switch and a second switch, the first switch of the first switching circuit and the second switch of the second switching circuit forming a first pair of switches, the second switch of the first switching circuit and the first switch of the second switching circuit forming a second pair of switches; each of the switches has an input terminal, an output terminal and a control terminal for receiving a signal for controlling the switch to be conductive or blocked; for each of the switching circuits, the output terminal of its first switch is connected to the input terminal of its second switch, the input terminal of its first switch being connected to a higher voltage, the output terminal of its second switch being connected to a lower voltage; the two terminals for connecting the motor are respectively connected to the input terminals of the second switches of the two switching circuits; the controller is adapted for controlling the first pair of switches and the second pair of switches to be alternately conductive and comprises a signal input terminal for receiving a switch control signal and a phase inverter for inverting the phase of the switch control signal; the controller further comprises a wiring board having a first to a fourth soldering pads, a first conductor and a second conductor, each of the conductors having two ends; the first soldering pad is connected to the signal input terminal, the second soldering pad is connected to an output terminal of the phase inverter, the third soldering pad is connected to the control terminal of the second switch of the first switching circuit, and the fourth soldering pad is connected to the control terminal of the second switch of the second switching circuit; and the two ends of the first conductor are connected to the first soldering pad and the fourth soldering pad and the two ends of the second conductor are connected to the second soldering pad and the third soldering pad; or, the two ends of the first conductor are connected to the first soldering pad and the third soldering pad and the two ends of the second conductor are connected to the second soldering pad and the fourth soldering pad.