Being microstep drive method of quarter-phase stepping

摘要

PROBLEM TO BE SOLVED: To provide a micro-step drive method of a two-phase stepping motor, capable of determining whether the two-phase stepping motor is in low-speed drive state or in a middle to high speed drive state regardless of the characteristics of the two-phase stepping motor to conduct drive control in a low speed range and drive control in the middle to high speed range.;SOLUTION: If a peak value of an excitation current flowing a motor coil reaches a reference current value before an electric angle comes to a first electric angle D1°, controlling is made in low speed range by estimating that a two-phase stepping motor 1 is in a low speed range to prevent noises caused by fluctuation of switching frequency. If the peak value of the excitation current flowing the motor coil does not reach the reference current value before the electric angle comes to the first electric angle D1°, controlling is made in the middle to high speed range by estimating that the motor is in the middle to high speed range to prevent an output torque from becoming zero, and drive control is performed based on the reference current value.;COPYRIGHT: (C)2011,JPO&INPIT