| 摘要 |
PURPOSE:To enable a given mode of speed adjustment control without the aid of any specially prepared hardware by driving a step motor with universal microcomputer utilized and a speed adjusting circuit made of a universal timer circuit. CONSTITUTION:The pulse rates of the periods corresponding to fn=f0+n are stored in the addresses N0-N0+n of the memory of a PROM 14 as illustrated to generate frequency f0+alpha after time t1, frequency f0+2alpha after time 2t1... and frequency f0+nalpha after time nt1 wherein startng frequency is f0, and calling is started with address N0 in order at the intervals of a fixed time t1, and a timer 16 is set accordingly. In the meanwhile, a timer 17 is set with speed adjustment time constant t1 and, upon the count-up of the timer 17, a CPU 13 is interupted. The timer 16 is set to timer rate f<n> by this interrupt and, upon the count-up of the timer 16, an excitation phase 19 is changed by + or -1 in accordance with the rotational direction. |
