Ignition system for extending the lifetime of gas filled electric lamps

摘要

The specification discloses an igniter circuit for extending the lifetime of a gas filled electric lamp. The igniter circuit includes a D. C. boost converter for generating an open circuit D.C. voltage for application to the lamp prior to ignition of the lamp. A resistance is initially connected between the converter and the lamp in order to limit the current applied to the lamp to a first predetermined level. A timer is connected to be energized concurrently with the D.C. boost converter in order to generate a timing signal after a predetermined time interval. A relay is responsive to the timing signal in order to establish a short circuit across the resistance in order to increase the current applied to the lamp to a second predetermined level higher than the first level. Current is not increased to the second predetermined level if the lamp ignites prior to generation of the timing signal. In this manner, the gas filled electric lamp utilizes only the current level required to sustain ignition, and therefore, the lifetime and reliability of the lamp and of the D.C. boost converter is extended.