Varistor is often connected in parallel in the circuit, when the resistance voltage changes at both ends of the resistor short-circuit current fuse fuse to protect the entire circuit. The role of varistor power supply overvoltage protection and regulation, today Xiaobian to share the work of the use of varistors in some of the experience and methods.
1, the voltage-sensitive voltage UN (U1mA): usually in the varistor through the 1mA DC current when the voltage is to indicate whether it is conductive, this voltage is called the varistor UN. The varistor voltage is also commonly used as the symbol U1mA. The error range of the varistor is typically ± 10%. In the test and the actual use, usually the voltage drop from the normal value of 10% as a varistor failure criteria.
2, the maximum continuous operating voltage UC: refers to the varistor can withstand long-term maximum AC voltage (RMS) Uac or maximum DC voltage Udc. General Uac ≈ 0.64U1mA, Udc ≈ 0.83U1mA.
3, the maximum clamping voltage (limit voltage) VC: the maximum clamping voltage value refers to the varistor applied to the specified 8 / 20μs wave current 9 (A) when the varistor voltage.
4, leakage current Il: to the varistor applied when the maximum DC voltage Udc current flow. When measuring leakage current, usually to the varistor plus Udc = 0.83U1mA voltage (sometimes with 0.75U1mA). Generally require static leakage current Il ≤ 20μA (also required ≤ 10μA). In actual use, the more concerned is not the magnitude of the static leakage current value itself, but its stability, that is, the rate of change after the impact test or under high temperature conditions. After the impact test or under high temperature conditions, the rate of change does not exceed one fold, that is considered stable.
1, the voltage-sensitive voltage UN (U1mA): usually in the varistor through the 1mA DC current when the voltage is to indicate whether it is conductive, this voltage is called the varistor UN. The varistor voltage is also commonly used as the symbol U1mA. The error range of the varistor is typically ± 10%. In the test and the actual use, usually the voltage drop from the normal value of 10% as a varistor failure criteria.
2, the maximum continuous operating voltage UC: refers to the varistor can withstand long-term maximum AC voltage (RMS) Uac or maximum DC voltage Udc. General Uac ≈ 0.64U1mA, Udc ≈ 0.83U1mA.
3, the maximum clamping voltage (limit voltage) VC: the maximum clamping voltage value refers to the varistor applied to the specified 8 / 20μs wave current 9 (A) when the varistor voltage.
4, leakage current Il: to the varistor applied when the maximum DC voltage Udc current flow. When measuring leakage current, usually to the varistor plus Udc = 0.83U1mA voltage (sometimes with 0.75U1mA). Generally require static leakage current Il ≤ 20μA (also required ≤ 10μA). In actual use, the more concerned is not the magnitude of the static leakage current value itself, but its stability, that is, the rate of change after the impact test or under high temperature conditions. After the impact test or under high temperature conditions, the rate of change does not exceed one fold, that is considered stable.
