Stepping motor driving apparatus

摘要

A stepping motor driving apparatus comprising: a stepping motor; a pointer which is operatively associated with rotation of the stepping motor; a sensor for detecting a stop position of the stepping motor; an updown counter for outputting a count corresponding to a position of a rotor of the stepping motor; a ROM for storing data on an excitation signal corresponding to the count of the updown counter; a digital-to-analog converter for converting the data of the ROM into a voltage signal; a drive amplifier for amplifying the voltage signal of the digital-to-analog converter so as to drive the stepping motor; a NAND circuit which seeks a non-conjunction of a sensor signal from the sensor and a signal outputted, when the count of the updown counter is "0", by the updown counter so as to output a mask signal; and an AND circuit which seeks a logical product of the mask signal of the NAND circuit and a clock signal inputted from outside so as to output a drive clock signal to the updown counter.