| 摘要 |
PURPOSE:To prevent burning of a stabilizer by electrically connecting a normally closed type thermal response switch and a safety device consisting of current limiting resistor in parallel to a luminous bulb housed within an external bulb of which inside is exhausted through a voltage multiplying smoothing circuit. CONSTITUTION:Even in case a luminous bulb 3 leaks and the filled Xe gas leaks into an external bulb 4 during the lamp is lighting and a Xe gas pressure in the external bulb is in the condition as low as about 0.1Torr, a voltage of about 100V which is about 2 times of the lamp voltage is applied across a bimetal 8a and electrode 8b of the normally closed type thermal response switch 8 of the safety device 7. Therefore, the glow discharge is certainly generated, the heated bimetal 8a is deformed making conent with a contact point 17 connected to current limit filament 9. A current flowing into a luminous bulb 3 is almost branched to the current limiting filament 9 and thereby the luminous bulb 3 goes out. Thereby, the safety device operates certainly, making off the luminous bulb and preventing burning of the stabilizer. |
