Circuit device for controlling the rotation speed of a DC motor

摘要

A circuit is proposed which compares a signal (A) corresponding to the motor rotation speed and a signal (B) corresponding to a specific desired rotation speed, in a phase detector (4). The rising edge of the signal (B) is placed with the signal (A) and a pulse-width comparison is carried out. The difference signal (C) between the pulse widths of the signals (A) and (B) is supplied to an integrating element (13, 14) which produces a peak voltage (D) corresponding to the difference signal (C). This peak voltage fixes a peak-hold memory (15) until the arrival of a further difference signal, an amplifier (16) which is connected downstream in consequence producing a control voltage (F) which is supplied to the motor (17) in order to adjust the rotation speed to the desired rotation speed. <IMAGE>