Dc motor one-way operation starting control circuit

Figure 2. 37 as the armature resistance, according to the principle of time starting control circuit. Diagram KA1 for current relay, KM1 for starter contactor, KM2, KM3 for short answer the starting resistance contactor, KT1, KT2 for time relay, the KA2 to owe current relay, R 3 for discharge resistance. Close circuit working principle is: the power switch Q1 and Q2 control switch, KT1 electricity, the normally closed contact disconnect, cut off the KM2, KM3 circuit. Ensure that when starting resistance R series 1, 2 R. Press the starting button SB2, KM1 electricity and self-locking, the main contact closure, turn on the motor armature circuit, armature into the secondary resistance starting, at the same time KT1 blackouts, KM2, KM3 electricity preparing sub armature loop resistance. At the same time, at the time of motor starting and pick up on opposite sides of the resistance R 1 KT2 electricity, open the normally closed contact, make KM3 not electricity, to ensure that R 2 series with the armature. After a period of time delay, KT1 time closing contact closure, KM2 electricity, sub R 1, as the motor speed increases, the armature current is reduced, to maintain a certain speed torque, starting process lieutenant general concatenated resistance resection, step by step in R 1 be short of in the meantime, KT2 coil power, after a certain delay, KT2 normally closed contact closure, KM3 electricity, sub R 2, motor running under full pressure, starting process is over.