Relationship between Voltage Value and Type Selection of Varistor

Nowadays, the varistor occupies a high market share and occupies an important position in the electronic components. For us, when we choose the voltage, the higher the voltage is, the better? The first thing to understand is the principle and function of varistors.

The voltage protection effect of a varistor in an electronic circuit, usually allowing electric shock with a current fuse or additional overvoltage protection. Working principle of varistor: voltage and current intensity of varistor identify special nonlinear relation. When the voltage applied on both sides of the varistor is lower than the nominal voltage, the resistance value of the varistor is close to infinity and the potential field flows through.

Voltage sensitive resistance is a certain voltage limit within a certain voltage limit protection element, if blindly select high voltage value, in the actual use of the situation does not have to produce such a high transient voltage, it has not reached the corresponding utility. If the voltage is low, it will often live in working conditions, not only is the duration of the interference, some even burned out. Now we choose 220V is 10K471, from the grid potential difference is about 260V, then the maximum electric voltage value is 1.414 / 260V / 368V, fill in the root sign 2's insurance coefficient to get our varistor value, in essence we can also estimate according to normal voltage 2 to 3 times.