| 摘要 |
<p>PURPOSE: To provide a ballast with small size and high operational efficiency by feedback connecting both ends of a secondary winding of a voltage transforming mechanism for switching current according to a vibration signal to a switching transistor, and forming an automatic transformer in which a primary winding generates flyback voltage according to the variation rate of current. CONSTITUTION: One end of a primary winding of a transformer 238 is connected to a power source 204, and the other end is connected to collectors 266, 270 of switching transistor circuits 252, 254. Both ends of a secondary winding 242 are connected to bases 260, 262, and emitters 264, 268 respectively in the relation of positive feedback. By periodical turning on and off of the circuits 252, 254, high frequency voltage is supplied to discharge lamps 202, 202' through inverter transformers 210, 212, and tuning capacitors 312-318. By this constitution, a ballast with small size and high efficiency is obtained.</p> |
