MOTOR CONTROL CIRCUIT

摘要

PURPOSE:To accurately control the rotating speed by charging and discharging a capacitor for obtaining the prescribed output voltage by the outputs of two counters which operates independently. CONSTITUTION:A frequency signal f1 from a frequency generator (FG)1a becomes output signals VQ1, VQ1 through a waveform shaper 2 and 1/2 frequency divider 3. Trigger signal generator 4, 4 generate trigger signals VT1, VT2. The first and second counters 5, 5 counts clock signal CLK synchronously with the rising edges of the signals VT1, VT2. This counting operation is always constant. A capacitor C1 is controlled to be charged and discharged through a NOR circuit 8, an AND circuit 9 and transistors Q1-Q3 by the combination of the level changes of the output signals of the first and second counters 5, 5. The rotating speed of the motor is controlled by the output signal of a capacitor C1.