What device automatically shuts off an electric current when it overloads?

A circuit breaker is designed to automatically shut off an electric current when it detects an overload. This protective device monitors the electrical flow and can interrupt the circuit to prevent further damage to the system or potential hazards such as electrical fires. Circuit breakers operate using a switch mechanism that can trip and break the circuit when the current exceeds a safe level, ensuring that the electrical system remains safe and functional.

Fuses also protect against overloads, but they do so by melting a metal wire inside them when current exceeds a certain level, thus requiring replacement once the fuse has blown. Transformers, on the other hand, are used to change the voltage of electricity, and rectifiers convert alternating current (AC) to direct current (DC), neither of which serves as a protective device for current overloads.