Overcurrent protection circuit for motor

　　Today we will introduce the overcurrent protection circuit of the motor. When the motor starts, press the lock button SBi once, and when the start is complete (after the motor speed stabilizes), press SBi again, and the protection circuit will start to work. For motors with a short start time (such as a few seconds), SBi can also use an ordinary button, as long as SBi is pressed during the start process.

　　When the motor operates normally, the secondary induced potential of the current transformers TAi~TA3 is small and is not enough to trigger the thyristor V. As shown in the figure below.