| 摘要 |
PURPOSE: To eliminate the dispersion of starting by connecting a predetermined resistor in parallel with a starting auxiliary circuit, which is formed of a non- linear ceramic capacitor, without opening this starting auxiliary circuit during the lighting, and forming only one electrical contact point. CONSTITUTION: Main electrodes 2a, 2b are sealed in both ends of a light emitting tube 1, and an auxiliary electrode 3 is sealed near the main electrode 2a, and the starting auxiliary gas, mercury and the metal halide are sealed inside of the light emitting tube 1. A starting circuit, which is formed by connecting a resistor 4 and a bimetal switch 5 to each other in series, is provided between the electrodes 3, 2b, and a series circuit of a non-linear ceramic capacitor 6 and a semi-conductor switch 7 is connected in parallel with the light emitting tube 1. Furthermore, a resistor 8 is connected in parallel with this series circuit, and a resistor 9 is connected in parallel with the semi-conductor switch 7. With this structure, even in the case where the resistance value of the resistor 4 is set at 15-200kΩand the resistance value of the resistor 9 is set at 15-100kΩthe pulse voltage at 1kV or higher is generated in the capacitor 6 by setting the resistance value of the resistor 8 at 10-100kΩ, and the startability is improved. |
