Timed photocell switch circuit
US5789868A · kind A · utility
17Cited by
45References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Aug 13, 1996 |
| Grant date | Aug 4, 1998 |
| Priority date | — |
| Expiry date | Aug 13, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A timed photocell switching circuit is disclosed which senses a light-to-dark transition and applies power to a lamp load for a preset period of time. After the preset period has expired the timed photocell circuit turns the lamp load off for the remainder of the night until a dark-to-light transition resets the circuit after which it can be triggered for another timing cycle. Once the light-to-dark transition triggers the timing cycle the ambient light level cannot disrupt the circuit. In addition, the circuit can be reset regardless of its timing position by momentarily cycling power to the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.