JPS5658788A - Motor speed controlling device - Google Patents

Abstract

PURPOSE:To perform a speed control of high accuracy and also to perform a control equal to the phase control by a method wherein clock pulses of a certain period are counted during a rotary period, and this content is read through a read out pulse and then, it is entered in an integrator to produce an error signal. CONSTITUTION:A revolution speed of a motor 1 is detected by means of a frequency generator 2 and this is entered in a read pulse generating circuit 5 via a wave form shaping circuit 3. Whereas, the output of a signal generating circuit 4 which transmits a clock pulse to be a referential frequency is entered in a counter 7, and further, clock pulses during one period of the output of the wave form shaping circuit 3 are counted. And then, this result is compared with the referential pulse number and depending upon the case whether acceleration or deceleration is made through a D/A converter 8, the results of the comparison are output as analog values of opposite polarity. This output value is read through a read-out pulse 5 corresponding to the revolution period and the charging and discharging of the integrating circuit 9 are performed to produce the error signal of the driving circuit 10.