Multi-unit slip motor synchronous operation speed control system circuit

The speed control system using the porcelain plate rheostat in the elastic frame-linked balance bridge for multi-unit synchronous adjustment
is shown in Figure 3-183. The speed control principles of other electromagnetic and photoelectric "elastic frames" are similar to this.
    In the figure, BQ2 is the excitation winding of the main slip motor (that is, it is used as the speed reference), and BQi and BQ3
are the excitation windings of the slip motor in front of and behind the main slip motor respectively.
    RPz is the master potentiometer, and adjusting it can change the speed of the entire system (ie, three slip motors). TGi~TG3
are three tachometer generators, which are connected to the electromagnetic clutch shafts of their respective slip motors. Adjusting the potentiometer 1RP1
(2RPi, 3RPl) can change the speed negative feedback voltage of each slip motor (which can cause the speed to change). lRP2
(2RP2, 3RP2) is a sensitivity potentiometer, which can be adjusted to change the speed of a corresponding slip motor. Porcelain disc varistor
RP. , RPb is used to coordinate the speed of three slip motors to make them run synchronously.