Patent · US Expired

Ballast circuit for metal halide lamp

US4904907A · kind A · utility

25Cited by
4References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 26, 1988
Grant dateFeb 27, 1990
Priority date
Expiry dateFeb 26, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S315/07
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A ballast circuit and method of operating gas discharge lamps are disclosed. The ballast circuit generates a relatively low frequency regulated square-wave current which advantageously provides for operating the gas discharge lamps during their run mode. The square-wave current delivered to the electrodes of the gas discharge lamp reduces or substantially eliminates the cataphoresis effects typically created by D.C. and 60 Hz operation of the gas discharge lamp while also reducing or substantially eliminating the detrimental acoustics resonance effects typically created by operating the gas discharge lamps at relatively high frequency of excitations.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.