View source for Fuse

A '''fuse''' is a device used to limit the [[current]] in a [[circuit]]. It consists of a thin [[conductor]] which has a slight [[resistor|resistance]]; when the current flow becomes too large, the energy dissipated in the resistor will raise the temperature of the conductor so that it fails.

Although they are very simple, and generally reliable, they have the disadvantage that, once actuated, they have to be replaced; they cannot be repaired. Although they were once common, they have generally been replaced with [[circuit breaker]]s (which perform exactly the same function); although they are still to be met with in special circumstances - e.g. if there is not enough room (e.g. on a [[printed circuit board|PCB]]) for a circuit breaker.

[[Category: Electrical Basics]]