| 摘要 |
PURPOSE:To conduct the lighting at a high input power factor by combining a DC generating circuit having a booster increasing function and a constant- current function with full wave bridge operating at low frequency. CONSTITUTION:An AC power source 1 is converted to DC current by a full wave rectification circuit consisting of rectifiers 2-5. A series circuit of an inductor 10 and a switch 13 operating at high frequency is connected to the DC output end of the full wave rectification circuit 2, and a series circuit of a rectifier 14 and full wave bridges 6-9 as inverters is connected in parallel to the inductor 10. The polarity of the rectifier 14 and full wave bridges 6-9 is the block polarity of the DC power source voltage, and the full wave bridges 6-9 are formed switches 6, 7, 8, 9. A parallel circuit of a discharge lamp 11 and a condensor 12 is connected to between midpoints of the full wave bridges 6-9, or the AC output end. Hence, a stable lighting can be achieved in an optional relation between the AC power source and the discharge voltage, and also a high input power factor can be obtained. |
