Coil tester

Impulse winding tester
Regarding Current When Applying the Voltage Pulses

The High-voltage DC charged in the HV capacitor (C), is discharged rapidly to the test coil (L) by triggering the gate of the Thyristor (SCR), which generates vibration waveforms. The Impulse test judges those waveforms.

The current, which flows out from the first capacitor is the maximum. This current can be calculated by the following expression.

The current, which flows out from the first capacitor is the maximum. This current can be calculated by the following expression.。

At the point A, the thyristor turns on and high-voltage is supplied. The current will be the maximum at the point B. The electric charge stops flowing from the capacitor and the current ceases to flow at the point C. If the apply voltage is 1800V, the voltage at the point A would be 1800V. As the point C is almost the same voltage as the point A, ΔV is considered to be 3600V.

Full-scale of the time-axis will be 25.6 μs at WIDTH "0"; 51.2 μs at WIDTH "1"; 102.4 μs at WIDTH "2"... if this waveform is shown as setting the WIDTH "2". Seeing this waveform on half of the screen, Δt is considered to be approx. 51.2 μs.

The capacitor of ECG's Impulse Tester is 0.01 μF, so the current will be calculated as follows:

The current will increase if the time-axis is short.