| 摘要 |
PURPOSE: To provide a control circuit, which inhibits the application of voltage for protection of a motor, when a stalled state occurs in an electronic commutation type of motor. CONSTITUTION: A tachometer pulse signal generator generates a signal which shows the rotational speed of the rotor of a motor 108. A first voltage inhibiting circuit 12 inhibits the application of a motor voltage to the winding of the motor 108, in response to the tachometer pulse signal, when the motor speed is under a preset lowest speed. A second voltage, inhibiting a circuit 114 inhibits the application of motor voltage to the winding, in response to the tachometer pulse signal, when the duty cycle of the tachometer pulse signal is outside of the preselected range where it is be acceptable. When the motor is stalling as described above, the application of motor voltage is inhibited. |
