Fluorescent lamp circuit with regulation responsive to voltage, current, and phase of load
US4791338A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1986 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Jun 26, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a fluorescent lamp, a "soft" start-up circuit initially applies a lamp, or inter-electrode, voltage which is limited to a peak voltage that will not start the lamp prior to heating of the lamp cathode to the proper temperature. The lamp cathode is then heated to the proper start-up temperature after which the lamp voltage is increased to a value well in excess of the ignition voltage required for all lamp types and operating characteristics in initiating lamp operation. The increased lamp voltage is applied in a pulsed manner until the lamp is ignited, whereupon the lamp may be operated at normal lamp current and cathode voltages or the lamp filaments may even be turned off with a consequent savings in input power.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.