| 摘要 |
PROBLEM TO BE SOLVED: To provide a half-bridge inverter for driving a fluorescent lamp that keeps the lamp from light out and can start it with optional brightness. SOLUTION: In this half-bridge inverter in which switching elements Q1, Q2 are alternately switched on and off by a high frequency switching circuit HFC and their outputs are converted into currents in the form of sine waves to be supplied to a fluorescent lamp FL, a transformer T1 is provided for stepping up the output voltage of the switching element Q2, and the ratio of the numbers of turns of the transformer T1 is set so that the secondary output of the transformer T1 when the lamp is not turned on is equal to or greater than the fluorescent lamp starting voltage. A preheating circuit is constructed of an independent circuit. |
