Patent ID: 6933699
Filing Date: 2005-08-23
Classification: H02P

Abstract:
1. A motor drive circuit that automatically corrects a rotation frequency of a motor, the drive circuit comprising: a speed control device having a sense-signal input terminal, a rotation-speed-signal input terminal, and a modulation signal output terminal, the speed control device simultaneously receiving a sense signal and a rotation speed signal through the sense-signal input terminal and the rotation-speed-signal input terminal, respectively, to generate a phase difference signal between the sense signal and the rotation speed signal and to generate, in a pulse width modulation manner, a pulse width modulation signal capable of modulating a duty ratio, wherein the pulse width modulation signal corresponds to the phase difference signal a real rotation frequency of the motor; a drive device having a first power output terminal, a second power output terminal and a signal input terminal, wherein the first power output terminal and the second power output terminal are coupled to the motor coil, respectively, and the drive device includes a plurality of transistors to generate a power drive signal, utilizes a sensor to generate a correction sense signal, and immediately feeds the correction sense signal back to the speed control device to form a closed loop control so as to automatically correct the rotation frequency of the motor; a drive timing controller coupled to the modulation signal output terminal of the speed control device and the signal input terminal of the drive device, the drive timing controller receiving the pulse width modulation signal and utilizing multiple switch elements to generate a timing control signal so as to control output timing of the power drive signal and prevent the short circuit of the driver device; a lock-up detection circuit connected to the drive timing controller, the lock-up detection circuit detecting a lock-up state of a rotor of the motor, wherein when the rotor is locked, the motor stops rotating to reduce power consumption; and a lock-up timing controller connected to the lock-up detection circuit, the lock-up timing controller modulating the lock-up detection circuit and intermittently starting the motor by adjusting the power drive signal.