PURPOSE: To generate a peak value and a high-frequency rush current by connecting a second capacitor in parallel to the first series circuit of a test contact, a first capacitor, a variable resistance for adjusting the rush current, and a variable inductance.

CONSTITUTION: A second capacitor C0 is connected to the first series circuit of a test contact S, a first capacitor C1, a variable resistance R for adjusting rush current, and a variable inductance L1 for adjusting rush current. The value of the capacitor C0 is set at a value much greater than that of the capacitor C1. A rush current is generated by the transient phenomenon of the capacitor C1, the resistance R1 and the series circuit of the inductance C1 and the capacitor C0. Therefore, even when the internal impedance and wiring impedance of a power transformer T are both high, a peak value and a high-frequency rush current can be freely generated by reducing the resistance R1 and the inductance L1.