Slow acting photo lamp control
US4697122A · kind A · utility
27Cited by
3References
8Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 1, 1986 |
| Grant date | Sep 29, 1987 |
| Priority date | — |
| Expiry date | Aug 1, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S315/07
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A room lighting control system which controls the electrical power supplied to the artificial lighting in an area based on the ambient light available. A photocell controlled digital lamp dimming circuit with particularly high stability for time and temperature is combined with a slow response time to avoid short term adjustments. A digital counter is used to determine a large number of steps over the adjustment range and the driving clock operates at a very low frequency, so that changes in light level take a relatively long time, and it takes an exceptionally long time to span the entire adjustment range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.