| 摘要 |
PURPOSE: To provide a discharge lamp lighting device capable of easily restarting lifting. CONSTITUTION: Voltage of a commercial AC power supply unit E is rectified with a full-wave rectifier 2, smoothed with a smoothing capacitor C1, and when voltage of a constant voltage element Q3 becomes a specified value or higher, the constant voltage element Q3 is turned on, a field effect transistor Q2 is turned on, then load current is detected with the primary winding of a current transformer CT. A field effect transistor Q1 and a field effect transistor Q2 are alternately turned on with a first secondary winding CT2a and a second secondary winding CT2b, the voltage is converted into high frequency with an inverter circuit 4 to start lighting of a fluorescent lamp FL. After the commercial AC power supply unit E is turned off, even if charges are remained in a commercial AC power supply unit E1 and the constant voltage element Q3 is turned on, current flows in the second secondary winding CT2b through resistance R4, and is used to a certain degree to charge a capacitor C5. Thereby, uneven magnetization of the current transformer CT is prevented. |
