DRIVE CIRCUIT FOR A BRUSHLESS MOTOR (as amended)

摘要

A drive circuit for a brushless motor comprising power lines for carrying an AC voltage, an inverter, and a controller. Each leg of the inverter is connected to a winding of the motor and comprises one or more bi-directional switches. The controller can output control signals that cause a pair of switches to conduct in one direction during the positive half-cycle of the AC voltage, and to conduct in the opposite direction during the negative half-cycle of the AC voltage. Alternatively, The controller can output control signals that cause a first pair of switches to conduct during the positive half-cycle of the AC voltage and a second pair of switches to conduct during the negative half-cycle of the AC voltage such that the winding is excited in the same direction irrespective of the polarity of the AC voltage.

主权项

1. A drive circuit for a brushless motor, the drive circuit comprising power lines for carrying an AC voltage, an inverter comprising one or more legs connected in parallel across the power lines, each leg connected to a winding of the motor and comprising one or more bi-directional switches, and a controller for outputting one or more control signals for controlling the switches, wherein the controller outputs control signals to turn on and off each switch multiple times during each half-cycle of the AC voltage, and the controller outputs control signals to excite a winding of the motor, the control signals causing a pair of switches to conduct in a first direction during a positive half-cycle of the AC voltage and to conduct in a second opposite direction during a negative half-cycle of the AC voltage.