Phase motor with inching automatic commutation circuit

As shown in the figure, SA1 and SA2 are travel switches; SB1 and SB2 are inching switches. Taking SB1 as an example, since it is a composite switch, pressing it will start the KMF and the motor will rotate forward. When you release it, the KMF will lose power, so the motor will be inched. When STF is pressed, since the normally closed contact of SB1 is in a closed state, KMF can protect itself and the motor can run for a long time. Taking SA1 as an example again, when the motor is running normally when STF is pressed, when the attached machinery hits the travel switch SA1, its normally closed contact is disconnected, the KMF circuit is cut off, and the motor stops; while at the same time, the normally open switch of SA1 When the contact is hit and closed, it is equivalent to pressing the start button of KMR, causing the motor to reverse. When SA2 is hit, the motor stops, but the normally open contact of SA2 is closed, and KMF is activated again, and the motor rotates forward. . In this way, over and over again, the motor realizes automatic reversal. This circuit is suitable for small electric motors.