Introduction to circuit breaker:
Circuit breakers act like switches which detects the faults occurred and stops the flow of current by saving the equipment from voltage overflows and short circuits. It can automatically come back to working when the faults are rectified. Generally the faults in the circuits occur due to in continuous flow of current or by improper arrangement of load elements. The circuit breakers can be designed accordingly for lower voltage circuits and higher voltage circuits. An AT89C52 micro controller is used for monitoring the circuit.
Circuit design and Working:
The microcontroller is fed with the rectified voltage coming from the rectifier. All the load elements are connected to a relay switch. The microcontroller monitors the voltage level required for the load elements, if it detects any change the voltage levels to voltage fluctuations then it automatically drives the relays to turn off. The rectifier bypasses the voltage levels and then the microcontroller again makes the relays turn on. These circuit breakers are mainly used as regulators in power circuits and in battery shunt circuits. The advantage of 89C52 is that it has a 8kb of flash memory which can be reprogrammed any number of times. A step down transformer is used to obtain the required current for the load elements present.
The circuit breakers are very effective in protecting the load elements from voltage over flows an short circuits. It can automatically switch when the faults occur, where as a fuse cannot switchover. It can be used for lower voltage circuits and higher voltage circuits. It is low cost model when compared to other circuit protecting devices.
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