Three-phase asynchronous motor forward and reverse manual control circuit

Circuit working principle: timer IC , together with inverter Ic3, form a bistable flip-flop
. When powered on, the output is low and the motor runs forward. If you press the switch SA. ,
the output becomes high level, and the motor runs in reverse direction. bistable flip-flop IC 2 and AND
gate IC. The two delay circuits are used to ensure that there is about a 5s gap time during the forward and reverse conversion process
to prevent short circuits when the current is switched; at the same time, the motor can be powered off first, and then the motor
can be started after the speed drops to reduce the starting current and Reverse impact, protect motor and mechanical device.