E.V. Vstavskaya, V.I. Konstantinov, V.V. Khateeva

Since discharge lamps have a nonlinear current-voltage characteristic with lots of small dynamic resistance, to work with them HID-ballasts are required. The most effective for today are low frequency electronic ballasts. A method of power control, based on limiting instantaneous current depending on instantaneous voltage and fixed power level is offered. To keep track of the instantaneous value of the lamp current the structure of indirect current measurement is proposed. Based on the output value of this structure, the controller transmits signals to open/close key input buck converter. The controller receives a power control signal, and thus lamp dimming can be realized. Use of this power control method in electronic ballasts increases efficiency, reduces losses of elements and stabilizes the output power.