Three-phase rectifier speed regulating circuit

It is suitable for occasions with large motor power. The main circuit adopts a three-phase bridge half-controlled bridge rectifier
circuit. In the figure, VD4 is a freewheeling diode, L is a filter reactor, KI is an overcurrent relay (for overcurrent protection
), and FU is a fast fuse (for short circuit protection). The trigger circuit consists of three sets of identical single-junction transistor phase-shift triggers
. The circuit is equipped with voltage negative feedback, voltage differential negative feedback and speed measurement negative feedback links. Adjust the master potentiometer RP3 to change
the motor speed.