| 摘要 |
A forward inverter ballast circuit employs a free-running oscillator (116); a transistor (118); a current-limiting (ballasting) network (120); and two fluorescent lamps (128). The transistor (118) is configured as a switch connected to be responsive to a signal generated (200) by the oscillator (116) and operative to periodically couple a line (234) to a circuit common. The current-limiting network (120) includes a diode (250) and a transformer (240) having a transformer primary winding (244) connected between a DC power-supply potential and the line (234); a first, tightly-coupled, transformer secondary winding (246) connected between the DC power-supply potential and the circuit common; and a second transformer secondary winding (248). In addition, the current-limiting network (120) includes an inductor (252), a capacitor (254), and another capacitor (256), all connected in series across the second transformer secondary winding (248). The lamps (128) are connected across one of the capacitors (256).
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