DC FUSE

 

DC FUSE

Fuse:

A fuse is a simple protective device that protects the circuit by disconnecting the current path. They vary in shape, rating, and size and can almost be found in any electrical circuit.

The simplest fuse is a simple resistive wire which is selected for its melting point, as the current passes through the wire it generates heat when the excessive current passes it generates more resistance and in turn more heat, which causes the wire to melt, thus creating a discontinuity in the circuit.

How To Select Right DC Fuse For Your Application:

The usage of the fuse is dependent upon the application, sometimes there is a simple need to disconnect the circuit in case current exceeds the limit, in other cases, there maybe a need to protect the circuit from overvoltage. We have different types of fuses; some common types are as follow:

Cartrige Fuse (Common Fuse) is the most common type of fuse used in the market, the simple construction makes it easy to use. A wire is placed in a glass envelope with terminals at a certain distance. The distance is maintained in DC fuses because the voltage is always at higher than 0V level, which increases the chance of creating an arc. The distant terminals reduce the chances of an arc being established in the circuit. The cartridge fuses are designed as slow blow and fast-blow fuses. The material of the fast blow fuse is sensitive to the spikes in the circuit and blows instantly in case of any current spikes.

Resettable / Polyfuse (Resettable Fuse), also called PTC fuse, is used in applications where fuse automatic resetting is required. These fuses work on the principle of positive temperature coefficient, as the temperature rises the resistance of the material of the fuse rises resulting in the termination of the current path. The path is restored as the temperature return to a nominal value resetting the fuse.

Overvoltage Suppression Fuses (Voltage Protection Fuse) are used in applications where we need to protect our devices from high voltages and high currents. They work on negative temperature coefficient NTC mode and are connected in parallel to the device as the temperature increases. The resistance decreases allowing the high current to take the lower resistance path.

Automotive Fuses are color-coded fuses used most commonly in cars. They are high-powered fuses and operate on a voltage range of up to 42V, whereas the current ratings vary for each color.

Semiconductor Fuses are used where we need not open and change the fuses over and over again, they have a very fast switching rate and most commonly used in electronics and mobile phones. They are extremely useful in devices where components are sensitive to small spikes in current. The electronics equipment deals with small current levels and is susceptible to damage from small current spikes.