Abstract: An inductorless ballast including four transistors arranged in a full-bridge configuration for supplying a high voltage AC step-type signal across a fluorescent lamp. The circuit of the present invention eliminates the need for an inductor, thereby resulting in a smaller, lighter and more reliable ballast which can fit into a fluorescent lamp socket.

Abstract: A model and computer program for designing the output stage of a high frequency electronic ballast for a fluorescent lamp. The user specifies a plurality of parameters relating to the operation of the fluorescent lamp, including lamp running power, running voltage, maximum preheating voltage for the lamp, minimum running frequency for the lamp, and an input voltage for the ballast. Based upon these parameters, the computer program calculates the values for various components of the ballast, including the inductor and capacitor of the output stage, such that the preheat frequency is greater than the ignition frequency, the ignition frequency is greater than or equal to the running frequency, the preheat voltage is less than the maximum preheat voltage, and the difference between the preheat frequency and the ignition frequency is greater than about 5 kHz.