A safety device that breaks an electrical circuit when it is overloaded.
The most commonly used fuse. Available in 5- to 30-amp sizes.
It has a threaded base like a light bulb and a small window to view a metal linkage. Electricity flows through the linkage. When the circuit is overloaded, the linkage melts and turns black, cutting off the flow of electricity through it. The fuse then must be replaced.