START CONTROL METHOD FOR BRUSHLESS MOTOR

摘要

PURPOSE:To realize smooth control of motor drive duty ratio at the time of starting through such starting control as a starting operation mode can be executed again only upon elapse of a predetermined time after finish of starting operation mode. CONSTITUTION:Starting process is executed according to a main program stored in a CPU 7 and a decision is made whether a signal is inputted from a throttle sensor 10 when r.p.m. of a motor 1 is lower than a stop decision r.p.m. A decision is made whether a predetermined time has elapsed upon provision of a signal from the throttle sensor 10, and driving signals are delivered from output terminals O1-O6 to a driving circuit 14 if the predetermined time has elapsed. The driving signals are then subjected to PWM control at a predetermined duty ratio. When a timer for limiting the execution times of starting process is provided, error of duty signal due to processing lag can be suppressed sufficiently and switching of starting process causes no hunting of duty ratio to be imparted to the motor 1.