| 摘要 |
PURPOSE:To raise impact resistance and ensure steady drive by making step control of the width of the driving pulses of an electromechanical converter driven in accordance with 2-phase drive pulses by the induction voltage of a driving coil. CONSTITUTION:The output of the flip-flops (FF)117 and 118 of a frequency dividing circuit 202 serves as the input of a pulse selecting circuit 206. In normal operation, small width pulses phi1 and phi2 are alternately generated from the outputs of a pulse converter circuit to drive a pulse motor driving circuit 204. The induction voltage generated from a driving coil 137 is detected by a detecting circuit 209 and the change-over of the pulse selecting circuit 206 of a pulse converting circuit 207 is made by thus-obtained signal. When impact load is received, the width of the output pulses phi1 and phi2 of the circuit 207 increases two times. When the induction voltage returns to the initial value thereof due to the increase of driving power, pulse width returns to the initial value thereof. |
