Control circuit for an inductive load

摘要

The circuit according to the invention controls the supply to an inductive load by a power transistor of the N-channel MOS type, placed on the side of the positive terminal of a supply source delivering a voltage +Vbat. The conduction of the transistor is maintained by means of a gate voltage Vs>+Vbat supplied by a voltage multiplier. On cutting off this voltage, there is blocking of the transistor and discharge of the load, which rapidly develops a high negative voltage. An interconnecting transistor than prevents the return to conduction of the power transistor while, according to the invention, a transistor of the P-channel MOS type isolates the gate of the interconnecting transistor to authorize the application to said gate of the negative voltage developed by the inductive load. The invention has application to the control of actuators for the automobile industry.