Alarm circuits to indicate the open status of circuit breakers or fuses for DC telecom and AC distribution circuits

摘要: An alarm circuit is provided which takes the place of auxiliary contacts that are generally used in association with breakers or fuses to provide an warning event breaker fuse series a load has opened for any reason. The high resistance resistor connected end breaker, and at other gain amplifier solid state switch. output remote signal relay, may be DC relay AC relay. arrangement such becomes conductive opens, thereby causing indication. Indicators associated circuits, including LED local indicative fact changed its state. A driven by change delay. Because monitors itself, true indication assured.