Code 232 SUPER FAST ELECTRONIC CIRCUIT BREAKER

The project is designed to shut down a power supply when it is overloaded by using a super-fast electronic circuit breaker. The concept of electronic circuit breaker came into focus realizing that the conventional circuit breakers such as MCBs take longer time to trip. Therefore, for sensitive loads, it is very important to activate a tripping mechanism at the shortest possible time, preferably instantaneously.

The electronic circuit breaker is based on the voltage drop across a series element proportional to the load current, typically a low-value resistor. This voltage is sensed and rectified to DC, and then is compared with a preset voltage by a level comparator to generate an output that drives a relay through the MOSFET to trip the load. The relay use in place of a semiconductor switch is preferred because such solid state switches would invariably fail in case of accidental short circuits. The unit is extremely fast and overcomes the drawback of thermal type. It uses a microcontroller from the 8051 family.

Furthermore, this project can be enhanced by using a CT for galvanic isolation between mains and control circuit. Power electronic devices such as high power thyristors / IGBTs can be used for ultra fast operation compared to the relay methods.