Overload current control circuit for direct current motor has voltage polarity switching circuit that controls the single polarity of the sampling voltage of the sampling resistor terminals

摘要

An overload-protection-and-detection circuit (50) is connected to the voltage polarity switching circuit (60) and a power MOSFET power semiconductor assembly control circuit (70). A direct current (DC) motor (10), a DC power source (20), a MOSFET power semiconductor assembly (30), and a sampling resistor (40) are connected in series. The voltage polarity switching circuit is connected to a circuit between the sampling resistor and the overload-protection-and-detection circuit. The single polarity of the sampling voltage of the sampling resistor terminals (41,42) is controlled.