Varistor is often used in parallel with the protected device or device, under normal circumstances, the DC or AC voltage at both ends of the varistor should be lower than the nominal voltage, even in the worst case of power fluctuations, it should not be higher than the maximum continuous operating voltage selected in the rated value, the nominal voltage value corresponding to the maximum continuous operating voltage value is the selected value.
For the application of overvoltage protection, the pressure-sensitive voltage value should be greater than the actual circuit voltage value, and the following formula should be used for selection: VmA=av/bc formula: a is the circuit voltage fluctuation coefficient; v is the DC working voltage of the circuit (effective value in AC); b is the pressure-sensitive voltage error; c is the aging coefficient of the component; The actual value of the VmA calculated in this way is 1.5 times of the DC operating voltage, and the peak value should be considered in the AC state, so the calculation result should be expanded by 1.414 times.
In addition, the selection of varistor must also pay attention to:
(1) It must be ensured that the continuous operating voltage will not exceed the maximum allowable value when the voltage fluctuation is maximum, otherwise the service life of the varistor will be shortened;
(2) When the varistor is used between the power line and the ground, sometimes the voltage between the line and the ground rises due to poor grounding, so a varistor with a higher nominal voltage than that used between the line and the line is usually used.
The surge current absorbed by the varistor should be less than the maximum flow rate of the product.
Advantages Various diameter sizes: SMD, 5mm, 7mm, 10mm, 14mm, 20mm, 25mm, 32mm, 34mm, 40mm, 53mm
Wide variable resistance voltage range: 18V-1800V
Multiple surge capacities: Standard, High Surge, Super High Surge
High current handling and energy absorption capacity
Single flow rate up to 70KA or higher
Fast response time
Low leakage current
Multiple lead types: Straight, bent and other special lead types
Various packaging forms: bulk, roll packaging, roll packaging