| 摘要 |
PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device with a small loss. SOLUTION: When the voltage of an arc tube 13 is heightened to generate starting secondary voltage when the arc tube 13 is not lit, voltage in a series circuit of a ballast choke L4 and a capacitor C5 is heightened. The ballast choke 14 is saturated and the resonance frequency of a main circuit 35 becomes high, but when it reaches the voltage of starting secondary voltage or higher, a Zener diode ZD3 is turned on, and a field-effect transistor Q3 is turned on, and thereby, a Zener diode ZD2 is short-circuited, and an inverter circuit 33 stops oscillation. A field-effect transistor Q1 is turned on between a gate and a source through the Zener diode ZD1 with DC voltage through a starter resistor R2, and pulse starting voltage having a pulse width of 500 μs is applied to the arc tube 13 with a starter 36. When the arc tube 13 starts, an inverter circuit 33 is operated, and high frequency is applied to the arc tube 13. |
