CONTROL METHOD, CONTROL SYSTEM AND TIME KEEPING DEVICE FOR STEP MOTOR

摘要

PROBLEM TO BE SOLVED: To provide a control method which can additionally reduce consumption power to drive a step motor installed in an electronic wrist watch and the like. SOLUTION: The invention is designed to possibly adjust effective power of driving pulse for each step motor's phase. In other words, driving pulse DP(i) with the effective power in each phase is supplied, the effective power of the driving pulse DP(i) is increased by certainly rotating the step motor by the driving pulse with fully large effective power when the step motor doesn't rotate and the effective power of the driving pulse DP(i) is decreased when it is confirmed that the step motor rotates by the driving pulse DP(i) of the same effective power for predetermined times. By repeating this for each phase, the step motor can be driven by the driving pulse which is suitable for each phase and small in effective power.