PURPOSE: To control a load on an exact timing, by consuming surge generated on the inductive load, thermally with a protective circuit, at the time of interrupting switching elements for protection.

CONSTITUTION: An inductive load 10 is energized by a DC power source 12 via a forward/reverse inversion circuit 11. The forward/reverse inversion circuit 11 is composed of the bridge-formed switching circuit of four switching transistors(Tr)13a-14b arranged on each side, and said load 10 is placed between connecting points 15-16. A connecting point 18 is connected to the negative pole of the power source 12 via a protecting Tr 20, and a protective circuit 21 is set in parallel with the Tr 20. Besides, by a control circuit 22, the protecting Tr 20 is turned conductive later than forward/reverse inversion Tr 13-14, and a period for feeding power to the load 10 and a period for feeding no power are selected by the protecting Tr 20. Then, the the interruption timing of the protecting Tr 20 is not delayed, and the load 10 can be certainly interrupted.