APPRATUS TO CONTROL THE FREQUENCY OF DRIVING POWER

A frequency controller can prevent the generation of heat of device and improve efficiency and control only the frequency without changing the duty width when the reference driving voltage is different from the driving voltage supplied to a plurality of loads. The frequency controller comprises the RT input terminal, PWM IC(200), open detection unit(210), auxiliary power supply part(230) and frequency control part(220). The PWM IC has the ERO terminal and open detect. And the transformer is controlled and the driving voltage of the constant size is outputted. The open detection unit detects the open phase of the multiple load driven by the driving voltage. The frequency control part is connected to the RT input terminal, and the ERO terminal and auxiliary power supply part.