In everyday life we are all more or less familiar with the word fuse. Basically a fuse is and electrical or electronic device that protect the circuit from some electrical fault like over current and over load. As fuse act as a weak link in the entire circuit, that’s why fuse can be considered as a sacrificial element in the circuit. Besides a fuse sacrifice itself and reliably open the circuit when there is an excessive current in circuit or the circuit is under overload and if there is any short circuit.
Yet the need for fuses is not unknown to us. Now the question is, how does the fuse work? The principle of fuse is based on the heating effect of electrical current. A simple consist of a small conductive material with low resistance and it is placed in series with the circuit.
The fuse is made with a conductive wire. The cross section area of this conducting material is designed such that it allows a certain amount of current that is permitted to flow in the circuit. When the current exceed this permitted value due to over load, short circuit or load mismatched, this excessive current will melt the conductive element in the fuse and open the circuit. By opening the circuit, the fuse will disconnect the power supply and thus the rest of the circuit is protected from being damaged. Fuse is very simple and cheap device that are being used for over hundred years as protective equipment.