Test transformers, or step-up transformers, are essential testing equipment for power stations, power distribution systems, research institutes and other users. They perform insulation strength tests at rated voltages on electrical products, equipment and insulating materials, to assess insulation performance, identify insulation flaws and test overvoltage resistance of the tested items.

AC and portable light-duty AC/DC high-voltage test transformers are made of premium cold-rolled silicon steel laminations. Their coils are of concentric pagoda-style multi-layer cylindrical design, with low-voltage coils inner and high-voltage coils outer. The portable housing brings advantages like compact size, light weight, sleek look and convenient movement.

Feed 220V power frequency power (380V for models over 10KVA) into the matching control box (console) (refer to its instruction manual for details). The autotransformer modulates the voltage to 0-220V/380V and inputs it to the test transformer’s primary winding. By electromagnetic induction, the secondary (high-voltage) winding generates power frequency high voltage with amplitude proportional to the primary-secondary turn ratio. This AC high voltage is rectified by a high-voltage silicon stack and filtered by a capacitor to produce DC high voltage, whose amplitude is a multiple of the AC high voltage’s effective value.

The product line includes three types: AC, AC/DC dual-purpose. Additionally, units with 200V taps can be connected in series to form a series-excited test transformer.