Effect of noise suppression by surge protective devices for impulsive noise

The response characteristics of surge protective devices for impulsive noise characterized by fast rise times are examined. These response characteristics are calculated in the time domain using an equivalent circuit model for a voltage clamping device. Calculated values were found to agree well with measured values and the appropriateness of the equivalent circuit model was demonstrated. Based on this model, the amount of inductance in low-capacitance devices was found to be a major factor in generating overshoot above the clamp voltage in the noise rising interval.