Patent ID: 7884564

Claim:
A control circuit of a sensorless motor, comprising: a first coil; a second coil; a first switch circuit electrically connected to the first coil for controlling a direction of a current flowing through the first coil; a second switch circuit electrically connected to the second coil for controlling a direction of a current flowing through the second coil; and an auxiliary switch circuit electrically connected to and between the first coil and the second coil for controlling the directions of the currents flowing through the first coil and the second coil by cooperating with the first switch circuit and the second switch circuit, wherein the first switch circuit, the second switch circuit and the auxiliary switch circuit are alternately turned on to make the control circuit form a full-bridge driving mode and to make the currents flow through both the first coil and the second coil, and the first coil and the second coil are electrically connected in series during a period of the full-bridge driving mode.