Low energy starting aid for high intensity discharge lamps

Claim 1

A light source comprising: a high pressure discharge lamp including a discharge tube having first and second electrodes sealed therein at opposite ends for receiving ac power and enclosing a fill material which emits light during discharge; pulse generating means operative to provide at an output thereof a high voltage, short duration pulse of predetermined energy; and a conductor including a generally straight portion extending from a region proximate to one of said electrodes towards a region proximate to the other of said electrodes coupled to said output of said pulse generating means and disposed in close proximity to an outer surface of said discharge tube for providing within said discharge tube an ionization path between said electrodes when said conductor is energized by said pulse generating means at which time said first electrode is at a first voltage potential, said second electrode is at a second voltage potential, and said conductor is at a third voltage potential higher than said first and second potential, wherein: said high pressure discharge lamp is a high pressure sodium discharge lamp; said fill material contains approximately 200 torr xenon pressure; and said pulse generator means provides a pulse of approximately 25 kilovolts for a duration of approximately 10 nanoseconds of approximately 10 millijoules energy.