Fuses & Varistors

In electricity, a fuse is a component consisting of a suitable support and a filament or sheet of a metal or alloy with a low melting point that is inserted at a specific point in an electrical installation so that it melts (by Joule effect) when the current intensity exceeds (due to a short circuit or excessive load) a certain value that could endanger the integrity of the installation's conductors with the consequent risk of fire or destruction of other elements.

On the other hand, a varistor is an electronic component with a characteristic curve similar to that of a diode. The term comes from the contraction of the English expression "variable resistor." Varistors are often used to protect circuits against voltage fluctuations by incorporating them into the circuit so that when activated, the current does not pass through sensitive components. A varistor is also known as a Voltage Dependent Resistor or VDR. The function of the varistor is to conduct a significant current when the voltage is excessive.