Low-Voltage Electronic Ballast Based on Class E Oscillator

In this paper, an electronic ballast based on the class E oscillator with a capacitive impedance inverter is presented. The ballast allows us to supply an instant-start fluorescent lamp from a 12-V dc power source. The class E oscillator allows us to increase efficiency using a simple structure with only one switch without a driving circuit. Due to the anti-parallel diode integrated into switch, the zero voltage switching conditions are fulfilled in the ignition mode, maintaining high efficiency. One of the applications of the ballast is in mobile equipment, where compact independent power sources are used, for example, batteries or solar cells. The ballast was designed with the following parameters: V_DD= 12V, P_o = 18W, f_o= 440kHz. The measured efficiency was 83%, the output power was 18.5W, and the dc power was 22.3W at the operating frequency of 444.44kHz