ADVANCES IN STARTING HIGH-INTENSITY DISCHARGE LAMPS

High-intensity discharge (HID) lamp starting includes three phases: el ectrical breakdown, cold-cathode glow discharge and thermionic are (ho t-cathode glow discharge). Recent enhancements in the understanding of these phases have stimulated the engineering of lamp-ballast systems to improve lamp maintenance and overall lamp starting properties. A la mp-ballast system approach allows for mutual compensation of lamp and ballast design for optimum starting and steady state operating charact eristics. The electronic ballst better utilizes present knowledge of s tarting requirements than does the magnetic ballast. In this review, r ecent advances in HID lamp starting will be discussed using results bo th from experimental and from theoretical studies.