| 摘要 |
PURPOSE:To achieve a high efficiency in a simple constitution by connecting a switching element between electrodes, and starting a lamp by putting it off after actuating a high frequency power source with the switching element on before lighting.1 CONSTITUTION:Actuation of a high frequency power source 7 is started with a transistor 11 on to be continuous. With a high frequency power outputted from a power source 7, its current heats filaments of electrodes 6a, 6b when the electrode 6a is at a positive potential. When the electrode 6a is at a negative potential, the electrodes 6a, 6b are shortcircuitted between each other through a rectifier element 9, and the current will not go to the electrodes. When the electrodes 6a, 6b are heated, a discharge start voltage is lowered, and the transistor 11 is put off in this condition to start discharge for lighting a lamp. While the lamp is lighted, the current does not go to the electrodes, so an unnecessary power consumption is eliminated. In such a constitution that a special power source for heating the electrodes is not used, a high efficiency can be achieved while lighting, and a power loss at the electrodes can be reduced during lighting. |
