Patent ID: 8344724

Claim:
A system for monitoring a circuit breaker of a circuit breaker unit, the circuit breaker unit comprising a circuit breaker panel and a door, the circuit breaker being positioned at the circuit breaker panel, the circuit breaker comprising a conductor, wherein a current when flowing in the conductor produces a magnetic field in a proximity of the circuit breaker, the system comprising: a first circuit to produce a carrier signal, the first circuit being positioned outside of the circuit breaker unit; a first magnetic coupler driven by the carrier signal, the first magnetic coupler being positioned outside of the circuit breaker unit on a first side of the door; a second magnetic coupler positioned inside of the circuit breaker unit on a second side of the door between the door and the circuit breaker panel, the second magnetic coupler being inductively coupled to the first magnetic coupler, the second magnetic coupler being configured to produce a regenerated carrier signal inside of the circuit breaker unit; a magnetic field sensor positioned in the proximity of the circuit breaker between the door and the circuit breaker panel, the magnetic field sensor being configured to produce a sensed signal in response to the magnetic field produced by the current when flowing in the conductor; and a mixer circuit positioned inside of the circuit breaker unit, the mixer circuit being coupled to the second magnetic coupler and the magnetic field sensor, to modulate the regenerated carrier signal in response to the sensed signal.