OVERCURRENT INTERRUPTING CIRCUIT

PROBLEM TO BE SOLVED: To obtain an overcurrent interrupting circuit applicable to a power supply circuit connected with a high capacity load by an arrangement wherein a main current path is not interrupted a detected overcurrent has a magnitude converging to a steady level in a short time. SOLUTION: When an operating switch 6 is turned on, a control circuit 5 sets the number of times (m) of switching signal for a semiconductor switch 1 at 1 and delivers a pulse signal to the logic circuit 3 of an IPS 4. Consequently, a main current circuit is conducted and the current flowing through the main current circuit is detected by a current detection circuit 2. The logic circuit 3 detects the overcurrent and interrupts the current flowing through the main current circuit before delivering a pulse signal to the control circuit 5. Consequently, the current flowing through the main current circuit is interrupted in a short time and since the value of (m), being set at 3, is delivered to the logic circuit 3, a current flows through the main circuit. The operation is repeated until the value of (m) reaches 5 and if the current level does not exceed an assumed overcurrent level, conducting state is sustained. The overcurrent interrupting circuit is applicable to a circuit connected with a high capacity load.