Abstract: A step-motor-driving device includes (a) a step-motor having driving-windings in plurality of phases, (b) an exciter for supplying power to excite driving-windings, (c) a position detector for detecting a position of a mover of the motor and outputs a position-detecting-signal, and (d) an excitation-timing-controller for receiving a driving-instruction-signal and a position-detecting-signal, and outputs an exciting signal to the exciter responsive to an input of one of the driving-instruction-signal and the position-detecting-signal.

Abstract: A drive control device for a stepping motor (1) includes a step signal generator (6) for generating a step pulse signal (e) at a constant interval of a period (T1), and an exciting signal generator section (2, 3) for generating an exciting signal in accordance with the step pulse signal, driving the stepping motor in accordance with the exciting signal, where the step pulse signal (e) with the constant period (T1) is obtained in the step signal generator based on externally supplied step data (a) including a step number (n) of a constant period (T0) designating a rotation of the stepping motor to a target position, and even when the step number of the stepping motor is increased in dividing a dummy sine wave stored in ROMs, the processing time of a microcomputer is not affected, attaining a high accuracy in step drive positioning of a stepping motor with smooth rotation thereof.