Surge Absorbers

Surge absorber (Metal Oxide Varistor) in a preliminary state, with respect to protected electronic components, has a high impedance (megohms) and will not affect the original design circuit characteristics. When the Surge voltage (more than the breakdown voltage of the surge absorber), the surge absorber impedance becomes low (only a few ohms) and caused a short circuit, and electronic products, or the more expensive of the group The pieces are protected.

The surge absorber - parameters

 A voltage temperature coefficient: refers to the varistor of the nominal voltage within a predetermined temperature range (temperature of 20 ° C to 70 ° C), the rate of change, i.e. the current through the varistor is kept constant, the temperature is changed by 1 ℃, the relative change of the voltage between both ends of the varistor.

2 current temperature coefficient: in both ends of the varistor when the voltage is kept constant, the temperature change of 1 ℃, the relative change of the flow through the varistor current.

Nominal voltage (V): through 1mA DC current when a voltage value of the both ends of the varistor(Metal Oxide Varistor)

4 voltage ratio: the varistor current of 1mA generated when the voltage value and the varistor current ratio of the value of 0.1mA when the voltage generated.

5 maximum limit voltage (V): refers to the value of both ends of the varistor can withstand the highest voltage.

Leakage Current (mA): leakage current is also called the standby current, refers to the varistor at a predetermined temperature and the maximum DC current flowing through the varistor current.

7 residual voltage ratio: the current through the varistor is a certain value, referred to as the current value of the residual pressure in the voltage generated across it. The residual pressure ratio is the ratio of the residual voltage and nominal voltage.

Through-flow capacity (kA): through-flow capacity is also known to pass traffic, time intervals and the number of times specified conditions (under the under the impact of the current standard is applied), allows a maximum pulse through the varistor ( peak) current value.

9 static capacitance (PF): refers to the inherent capacitance of the varistor.

10 Insulation resistance: refers to the resistance value between the insulating surface of the lead line (pin) of the varistor and the resistor.

11. Voltage nonlinear coefficients: the varistor under the action of a given applied voltage, the static resistance value and the ratio of the dynamic resistance values.(Metal Oxide Varistor)