Patent ID: 8816626
Filing Date: 2014-08-26
Classification: H02P

Abstract:
1. A motor drive control device comprising: a voltage detector; an A/D conversion section; an initial acceleration controller; output drive controllers; an output driver; and a current detector; wherein the output driver includes a plurality of power transistors and an output pre-driver, the power transistors being adapted to drive a multiphase DC motor, the output pre-driver being adapted to drive a plurality of input electrodes of the power transistors; wherein the current detector is capable of detecting a motor drive current that flows to the multiphase DC motor, detected information about the motor drive current being converted to a current detection digital signal by the A/D conversion section; wherein the output drive controllers supply PWM drive output signals for PWM drive to the output pre-driver in such a manner as to minimize the error between a current instruction signal and the current detection digital signal; wherein the voltage detector is capable of detecting an induced voltage developed across a stator coil of each phase of the multiphase DC motor and generating a detected induced voltage; wherein, when the multiphase DC motor starts up, the initial acceleration controller becomes controlled and placed in an operating state, and in response to the detected induced voltage generated from the voltage detector, supplies a plurality of initial acceleration output signals specifying a conducting phase for initial acceleration of the multiphase DC motor to the output drive controllers; wherein the initial acceleration controller, the output drive controllers, and the output driver make a conducting phase change and perform the PWM drive to provide the initial acceleration of the multiphase DC motor in response to the detected induced voltage and to the error upon startup of the multiphase DC motor, and wherein upper-limit duty values for the PWM drive output signals to be supplied from the output drive controllers to the output pre-driver during the period of the initial acceleration can be arbitrarily set in the output drive controllers.