what type of an electronic circuit can i add on this rccb so that it can be called an electronic type of an rccb, i really need to add an electronic circuit for this for my electronics class, help anyone
Residual circuit breakers are used to shut off the power when an earth leakage is detected, thus protecting the user from electric shock. They work by sensing the difference in current flowing through the live and neutral conductors. This is done using a current sense transformer with both the live and neutral conductors wound in phase with each other. Under normal operating conditions the magnetic fields cancel, but when more current is flowing through the live than the neutral a magnetic field is generated which trips the breaker.
Another way of protecting against electrical shock is to use an isolation transformer, but this is normally only used for smaller appliances (e.g electric razors) as they are big and bulky.
Note that RCDs and isolation transformers don't completely protect you from electrical shock; there is no way of protecting against a shock from phase to neutral or phase to phase.
RCD stands for Residual Current Device, as Hero999 said. And usually have 2 poles/contacts. If you want something that will protect an electronic circuit, a Single Pole MCB will suitable. You just need to find one close to the current of the supply. Lowest i've seen are 2 amps. usually they will have the amperage printed onto them, with a C in front. for a 2 amp unit, C2 would be there. is that it?