| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein a filter is required for using a current signal for control since motor current is intermittent current which is PWM-controlled and a complex waveform shape results, where the current which passes through motor winding from a power supply the positive side and flows to the power negative side and current which passes through motor winding from the power negative side and is regenerated to the power positive side are repeated, and wherein the number of components of a drive circuit increases, when the filter is constituted by hardware by an analog circuit and that processing time increases, when the filter is constituted of CPU software. SOLUTION: In the drive circuit of a two phase stepping motor for unipolar wire connection or bipolar wire connection, which is driven by a triangular wave comparison phase complementary PWM system, a combined value of current flowing in all windings of an A phase and a B phase is detected with one current detection resistor. A current control system is simplified by feedback-controlling the combined current value. A filter is dispensed with by varying the sampling of an A/D converter used, when the size of motor current is input to CPU according to the electrical angle. COPYRIGHT: (C)2008,JPO&INPIT |
