High-pressure discharge lamp with pulsed inverter operating circuit, and method of operating a discharge lamp

摘要

To ensure ignition of a high-pressure discharge lamp, for example a metal vapor halogen high-pressure dicharge lamp which has an ignition circuit, and is operated by direct current from an inverter circuit controlled for pulse width modulation, current flow to the lamp is extended in time upon initial energization thereof so that an initial hot spot which forms on an electrode can remain hot to establish a stabilized arc. This extension of current flow can be obtained by an R/C circuit in parallel to the output or storage capacitor (CA) of the inverter circuit (FIG. 1) or by an NTC resistor (H) in series with the lamp, or by a resistor which is short-circuited by a relay contact as the lamp operates, or the like.