Patent ID: 6054834
Filing Date: 2000-04-25
Classification: G05B

Abstract:
A system for controlling a step motor which obtains a driving torque by exciting a plurality of phases, comprising:a position detector for detecting a position of said step motor;a phase detector for detecting an excitation state of said step motor;a step motor control unit for generating a driving signal to control start and stop operations of said step motor to be performed in specific phases based on the position of said step motor as detected by said position detector and the excitation state as detected by said phase detector; anda step motor driving unit for driving said step motor in response to said driving signal generated by said step motor control unit;wherein said step motor control unit comprises:a read-only memory (ROM) for storing a control program, specific excitation states of said step motor, and a target movement of a step of said step motor;a central processing unit which detects a stop position by comparing position detection data of said position detector with the target movement of the step stored in said ROM, detects a phase of the stop position from said phase detector, and generates a control signal; anda phase signal generator for providing a driving pulse to said step motor driving unit in response to the control signal from said central processing unit.