Reduced voltage and time delay to eliminate filament hot shock
US6208090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 2000 |
| Grant date | Mar 27, 2001 |
| Priority date | — |
| Expiry date | May 5, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B39/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method to eliminate filament hot shock in lamp filaments, particularly in compact filament light sources such as high efficiency infrared reflective coated halogen lamps, during installation or during energization comprising a voltage reduction circuit that reduces the voltage applied to the lamp filaments for a predetermined period of time and a timing circuit that is activated each time the lamp is energized and controls the predetermined period of time during which the voltage reduction circuit reduces voltage applied to the lamp filaments. Optionally, a one time latch circuit may be included that enables the timing circuit upon energization and disables it after the voltage reduction circuit has operated continuously for the predetermined period of time, and forever thereafter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.