Research on OC gate current limiting circuit used in serial motor control

An OC gate current limiting circuit which breaks through the traditional way,limits the motor current directly without detection and protects the motor current directly by hardware circuit is proposed based on the traditional limiting method which monitors the motor current and then limits it for motor protection by Holtz and magnet ring.The voltage drop produced by letting the preset maximal current pass through the switch is taken as the reference voltage,and letting the real current pass through the switch is taken as the comparing voltage value.When the real current is greater than the preset maximal current and the comparing voltage is greater than the reference voltage,the OC gate circuit will shut off the signal control circuit which generates the control signal of the switch.Otherwise,when the real current is less than the preset maximal current,the switch works normally.Therefore,it can quickly limit the current to the preset maximal current when the current surges over the preset maximal current.The results show that the circuit has the characteristics of short response time,high control precision and low cost,etc.