Circuit Breaker

The advent of electrical wiring

Not too long ago, when electrical wiring was first being built into houses, many people fell victim to physics. The unfortunates would plug too many appliances into their circuit. Each appliance drew a certain amount of current. When current is resisted, it produces heat proportional to the square of the current times the resistance (shown mathematically as $I2R$). Because houses lacked superconducting home wiring, this hidden coupling between electronic gizmos made the wires in the walls get hot, sometimes hot enough to catch fire.

The electrical fuses

The fledgling energy industry found a partial solution to the problem of resistive heating in the form of fuses. The entire purpose of an electrical fuse is to burn up before the house does. It’s a component designed to fail first, thereby controlling the overall failure mode. This brilliant device worked well, except for ...