| 摘要 |
PURPOSE: To provide an inductor step-up transformer with a tap which effectively acts in particular as a ballast operating a gas discharge lamp. CONSTITUTION: An inductor step-up transformer with a tap is provided with one pair of input terminals 16, 18 which receives an input voltage from a DC source 14, one pair of output terminals 20, 22 which feeds an output voltage of the input voltage or more to a gas discharge lamp 12, an inductor L1 with a tap which has first winding L1 A and second winding L1 B, an active switch S1 which controls the current of the first winding L1 A, and an passive switch D1 which controls the current of the second winding L1 B and a first capacitor C1 . A device which changes the clamp voltage of the active switch S1 corresponding to the change of the output voltage, and a clamp capacitor Cc which transfers accumulated energy in the leak inductance of the inductor L1 to a load in order to improve efficiency are further provided. First filter is formed of the first capacitor C1 and the clamp capacitor Cc , and second filter is connected to the output terminals 20, 22. |
