| 摘要 |
PURPOSE:To improve stability by providing a counter that counts up and down based on the voltage comparison result of motor speed and speed control, and by changing the pulse width, etc., of driving pulses with its output converted to analogue. CONSTITUTION:A PWM circuit in an oscillatory wave motor drive circuit compares the output of an F/V converter 9a with the speed control voltage VSP by a voltage comparator 9d. This output is supplied to a control terminal of an up/down(U/D) counter 9e, the outputs Q1-n of which are inputted into a comparator 9c through a D/A converter 9f of a voltage adder. If, then, the output of the D/A converter 9f is zero, the pulse width will be maximum as the output of the comparator 9c is always 1 and the motor applying voltage will be maximum. Conversely, if the output of the D/A converter 9f increases, the motor applying voltage will reduce. |
