Fluorescent lamp brightness control
US4792729A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 31, 1986 |
| Grant date | Dec 20, 1988 |
| Priority date | — |
| Expiry date | Jul 31, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A load side phase control circuit is used in conjunction with a conventional fluorescent light ballast (step-up autotransformer) and an isolation transformer to achieve fluorescent lamp brightness control. A resistor and capacitor connected in series shunt the phase control circuit to maintain low level illumination even when the phase control circuit is nonconducting and also provide a transient suppression when the phase control circuit switches to a conducting state. The circuit is especially suited to printed circuit board preassembly and subsequent connection to the lamp and ballast by a one step crimping operation. The resulting fluorescent lamp system--of the rapid start type--is well suited for use as a task light where the lamp is mounted relatively close to an underlying work area and receives power from a conventional outlet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.