Direct current speed servomotor of pulse conduction system

Abstract

Abstract PURPOSE:To prevent the wear of motor brush and to realize a long lifetime of a motor, by adding a duty ratio detecting circuit and a variable drive voltage supplying circuit to a servomotor of pulse conduction system and reducing the motor supply voltage during a constant speed operation and reducing the level of noise. CONSTITUTION:When a start command 1 is supplied to a reference clock oscillator 2, a clock 3 is oscillated. And the difference of phase between the clock 3 and an output pulse 5 of an encoder 11 attached to the same shaft as a motor is detected by a phase detecting circuit 4. The duty ratio between the phase difference signal and the reference clock signal is detected by a duty ratio detecting circuit 27. When this duty ratio is becomes less than a certain set value, the driving voltage 30 to be supplied to a switch type driving circuit 7 is set at a low level by a driving voltage circuit 28 to be supplied. The voltage to be supplied to the circuit 7 is set a high voltage level 38 from time 19 to 31 as the start value and in the sections during which the duty ratio is higher than a certain set value. The conduction dyty ratio is reduced as the speed of revolution increase and becomes less than a certain set level. Thus the duty ratio is lowered toward a low set value 39 at the time 31.

Inventors

• 👤 Akio Nagai

Bibliographic Details