Varistor is a voltage-sensitive resistive device with nonlinear volt-ampere characteristics. Its resistance value will change with the change of voltage. It is mainly used for voltage clamping and absorbing excess current when the circuit is under overvoltage. To protect the subsequent components.
When overvoltage occurs, the varistor uses nonlinear volt-ampere characteristics to clamp the overvoltage to a relatively fixed voltage value to protect the subsequent circuit, which plays an important role in electronic products.
Varistors are widely used, but one disadvantage is that they are easy to age. In actual use, varistors will easily age due to the installation environment or current impact. The easy aging of varistors has adverse effects on electronic products, which will seriously interfere with the normal operation of electronic products, greatly shorten the working time of electronic products, and cause unnecessary losses to consumers.
In order for electronic products to work normally, it is necessary to solve the easy aging of varistors. So how to solve the easy aging problem of varistors? Use a ceramic discharge tube and a varistor in parallel.
The varistor is connected in parallel with the ceramic discharge tube, which can solve the problem of performance degradation of the varistor after passing a continuous large current, and delay its aging speed.
When the varistor is connected in parallel with the ceramic discharge tube, the varistor starts to work before the discharge tube is turned on, clamps the overvoltage and discharges the amplified current. After the discharge tube is turned on, it is shunted in parallel with the varistor, which reduces the flow pressure on the varistor and avoids performance degradation and aging of the varistor due to high current impact.
When the varistor is connected in parallel with the ceramic discharge tube, one problem should be paid attention to: the reference voltage of the varistor should be greater than the voltage of the ceramic discharge tube. If the reference voltage of the varistor is too low, the current will be absorbed and released by the varistor when the voltage is over, and the performance of the varistor will degrade after passing a continuous large current. The reference voltage of the varistor is greater than the voltage of the ceramic discharge tube.
By solving the aging problem of varistors, electronic products can be used for a longer period of time and play their due role.
Post time: Jun-26-2024