Control transformers are compact dry-type transformers. It is often applied as a transformer for supplying power to machines, electrical machinery, relays, lighting, etc. As a power supply system for control circuits in electrical equipment. Control transformer is suitable for AC 50Hz/60Hz, voltage 1000V and the following power supply circuit, which can work continuously for a long time at rated value. Control transformers operate on the basic principle of the magnetic effect of current. Control transformer consists of transformer core and coil transmission line. It has two coils, the primary coil and the secondary coil. The secondary coil is outside the primary coil. When the primary coil is connected to the AC current, the transformer core creates an alternating electromagnetic field and the secondary coil creates an induced current. It can not only change the voltage of the AC current, but also change the characteristic impedance. And it can change the flow of electricity without exceeding the output power of the design scheme. ATO offers more reliable control transformers at a more affordable price.