Ignitional run circuit that immediately applies only a DC voltage after lamp ignition but before the main AC potential is applied

US5770924A · kind A · utility

Assignee

• Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH · DE

Inventors

• Josef Osterried · Ottobrunn, DE
• Andreas Huber · Holzgerlingen, DE
• Alwin Veser · Hallbergmoos, DE
• Frank Hansmann · Bocholt, DE

Key dates

• Filing date: Mar 4, 1996
• Grant date: Jun 23, 1998
• Expiry date: Mar 4, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02B20/00
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

To largely, or entirely inhibit glow discharges during the start-up or run-on phase (Ta) of a high-pressure discharge lamp, the lamp is operated in a second time period (T2) immediately after ignition (T1) with continuous direct current during which the electrode of the lamp which then functions as an anode has reached emission temperature; in a third time period (T3), the polarity of the direct current is reversed and the other electrode, which now will function as an anode, is heated to emission temperature; thereafter, alternating current energy is supplied to both electrodes, typically in frequencies between 90 and 150 Hz. A suitable second time period (T2) can be about 2 to 21/2 second, the third time period (T3) being shorter. The total warm-up time may extend to a minute or more; current being supplied during the second, third and subsequent periods is usually higher, for example by a factor of 1.5 of the normal or rated operating current.