Coil tester

Impulse winding tester
How to set the Apply Voltage

Thank you very much for choosing our Impulse Winding Tester, DW Series.

*How should I set the Apply Voltage?

When applying voltage pulses to both ends of the coil, judgement of whether the coil is safe or in danger of burn out should be made using the design data. Our Impulse Tester charges a high-voltage capacitor (0.01μF), and using a thyristor as a switching element, applies the voltage to the test coil. For this reason, since the waveform varies widely depending on the test coil, it is quite difficult to select the best apply voltage.

Here, we introduce a method for obtaining the apply voltage relatively easily.

First of all, connect the good quality coil to the Impulse Tester. Then, apply voltage starting from a low level and gradually increase it. You will see the waveform assume a neatly thin line when applying the lower voltage. After increasing the voltage, the upper and lower portion of the waveform will become slightly thick and you will soon see the waveform as scatted dots. These dots are caused by noise discharge, proof that there has been change in the test coil insulation by applying high voltage even though it is a good quality coil. The voltage at which this state appeared will provide an indication of the apply voltage for the test coil. Try it with several good coils and find the most accurate voltage value. On the basis of this voltage, determine the apply voltage by raising or lowering the voltage, depending on the operating conditions of the test coil.

For example, reduce the value 20% for a comparatively moderate use coil. For coils which, though used severely, are made of strong wire, raise the voltage 20%. For most coils, even though noise discharge may appear, they are not considered to be defective. Please use this noise discharge effectively to distinguish between coils.

For more details, please refer to the "Flutter Judgment" and "Application Technique" in the Instruction Manual.