In
electronics and
electrical engineering, a
fuse (from the French
fusée, Italian
fuso, "spindle") is a type of low resistance
resistor that acts as a
sacrificial device to provide
overcurrent protection, of either the load or source circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, interrupting the
circuit that it connects.
Short circuits, overloading, mismatched loads, or device failure are the prime reasons for excessive current. Fuses can be alternative to
circuit breakers.