As the use of inverter coil will increase in the future, such as house hold appliances,　automotive coil, industrial commodity,　the examination of such coils will spread and must be done.

With the spread of inverter coil, the reliability of insulation test is required including partial discharge, such as appliances and automotive products, used for industrial products, motors, transformers, etc., and the coil insulation examination of the motor and the transformer can be done at the same time as examining layer short according to the voltage of the impulse surge. It is an epoch-making test fixture to be able to reduce costs and shorten test time.