The test transformer, also known as a step-up transformer, is a fundamental testing device for users such as power stations, power supply and distribution systems, and research institutions. It is used to conduct insulation strength tests on various electrical products, electrical equipment and insulating materials at specified voltages, evaluate the insulation level of products, detect insulation defects of the tested objects, and measure the ability to withstand overvoltage.

AC test transformers and light-duty AC/DC high-voltage test transformers are laminated with high-quality cold-rolled silicon steel sheets. The coils adopt a concentric pagoda-shaped multi-layer cylindrical structure, with the low-voltage coil inside and the high-voltage coil outside. The shell is portable, featuring small size, light weight, elegant appearance and easy mobility.

Connect a power frequency 220V power supply (380V for products above 10KVA) to the control box (console) — a supporting device for the test transformer (see the control box (console) instruction manual for detailed information). The voltage is adjusted to 0-220V/380V via an autotransformer and input to the primary winding of the test transformer. Based on the electromagnetic induction principle, the secondary (high-voltage) winding obtains a voltage amplitude of the same multiple as the turn ratio of the primary winding, i.e., power frequency high voltage. This power frequency high voltage can be converted into DC high voltage through rectification by a high-voltage silicon stack and filtering by a capacitor, with its amplitude being the multiple of the effective value of the power frequency high voltage.

This product series is divided into three categories: AC type, AC/DC dual-purpose type. Meanwhile, the transformers with 200V taps can be connected to form a series-excited test transformer.