Fuse

In electronics and electrical engineering, a fuse sis a type of low resistance resistor that acts as a device toprovide over current protection, of either the load or source circuit. It's essential component is a metal wireor strip that melts when too much current flows, which interrupts the circuit in which it is connected. Shortcircuit, overloading, mismatched loads or device failure are the prime reasons for excessive current.A fuse interrupts excessive current (blows) so that further damage by overheating or fire is prevented.Wiring regulations often define a maximum fuse current rating for particular circuits. Over current protectiondevices are essential in electrical systems to limit threats to human life and property damage. Fuses areselected to allow passage of normal current plus a marginal percentage and to allow excessive current onlyfor short periods. Slow blow fuses are designed to allow higher currents for a modest amount of time longer,and such considerations are and were commonly necessary when electronics devices or systems hadelectronic tubetech or a large number of incandescent lights were being powered such as in a large hall,theater or stadium. Tubes and incandescent lights each have reduced current needs as they heat up tooperating temperatures for their internal resistance grows as they are heated— the same physics principlecauses the fuse material to melt, disconnecting the circuit from power.