Four lamp modular lighting control
US4523130A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1984 |
| Grant date | Jun 11, 1985 |
| Priority date | — |
| Expiry date | Mar 28, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention is directed to a circuit and a method for efficiently controlling the output illumination level of a gas discharge lighting arrangement having four or more gas discharge lamps with multiple ballasts. Load side control of each ballast is provided by a timed interval controlled impedance, serially coupled between the particular ballast and its associated lamps. A circulating inductor, coupled in parallel with each controlled impedance, provides a current path between the power source and the lamps at least during that portion of the AC waveform when the controlled impedances are non-conducting. The invention is equally operable at both 120 volt and 277 volt AC levels without major component changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.