This article describes an electronic circuit breaker, combining current sensing with timing to create an energy- tripped breaker, which protects sensitive circuits while minimizing nuisance trips.
The document presents a design for an energy-tripped circuit breaker. Unlike standard breakers that trip based solely on current, this design combines current sensing with a variable time delay to protect sensitive circuits while ignoring brief current spikes.
The core of the design utilizes the LT6108-2 current sense amplifier and the LTC6994-2 Timerblox delay timer. The circuit automatically resets after a fault condition clears, but includes a retry mechanism that can be adjusted via an optional resistor to allow more time for faults to subside before reapplying power.
The example circuit uses a trip threshold of 500mA.
Higher load currents result in shorter delay times; for instance, a 5A load trips the breaker in only 60ms.