MALFUNCTION PREVENTING CIRCUIT OF A LEAKAGE CURRENT CIRCUIT BREAKER CAPABLE OF PREVENTING THE MALFUNCTION OF A SILICON CONTROLLED RECTIFIER DUE TO A HIGH FREQUENCY SIGNAL

摘要

PURPOSE: A malfunction preventing circuit of a leakage current circuit breaker is provided to prevent the malfunction of a SCR(Silicon Controlled Rectifier) by removing a high frequency in an input signal connection terminal of an integrated circuit even though a high frequency is induced from a ZCT(Zero Current Transformer).;CONSTITUTION: A ZCT(31) detects a zero phase current by sensing the current variation of a power line. An IC(21) outputs a trip signal if the voltage of an inputted signal through the ZCT is larger than the reference voltage. A SCR(15) is turned on by applying a trip signal from the IC to a gate terminal. A trip coil(11) blocks a power line from a load by operating a trip switch with a current which is excited by turning on the SCR. A first high frequency removing element is serially connected between the ZCT and a first input signal connection terminal of the IC and is comprised of a bead, a coil, or three terminal condenser. A first condenser is branched between the first high frequency removing device and the first input signal connection terminal of the IC and is connected in parallel to the IC. The high frequency signal inputted to the first input signal connection terminal of the IC is removed by forming an LC resonant circuit using the first high frequency removing element and the first condenser.;COPYRIGHT KIPO 2011