It is a device applied to convert a high voltage of main circuit to a lower voltage so as to supply power to the control equipment that need above average voltage regulation when started and cannot be connected to the main circuit. Control transformers are perfect for working in combination with industrial starter circuits.
Using a control transformer ensures lower, safer and also very effectual control circuit voltage which is apt for application in high working voltage applications. Employing lower voltages in control circuit safe-guard the workers who use on & off switches in dangerous environment. High voltages are not apt for safety of some appliances like control Panels, Medical Equipment and Inverter etc. Hence Control transformers are vital for their working.