Control transformer is transformer which supplies power to control and or auxiliary equipment not intended for direct connection to the main circuit. Control Transformers are specifically used to provide control supply voltage for the control circuits of AC motor starters i.e. starter coils, timer, indicating lamps, etc. The Industrial Control Transformer are manufactured to meet this specification. These can be of the single phase version or the three phase version from 1 KVA to 100 KVA.