PURPOSE: To provide a commutation type d.c. circuit breaker, by which matching of the action timing between a main contact point and an instantaneous contact switch is facilitated, and which has a stable circuit breaking performance.
CONSTITUTION: An electromagnetic repulsion coil 5 is provided in the vicinity of a short ring 7 connected to the moving electrode 1B of a main contact 1. The electromagnetic repulsion coil 5 is connected to a commutation circuit 6, and the electromagnetic repulsion coil 5 is magnetized by the discharge current I2 of a capacitor 4 run by closing the instantaneous switch 3 of the commutation circuit 6, to provide operation force for closing the main contact 1. The discharge current I2 running reverse to a main circuit current I1 is fed to the main contact point 1, to form a current zero point on the main circuit current I1.
HONDA HARUO
OUCHI SHIGETOSHI
OIDE SHINICHI
