Outdoor lighting control apparatus
US5325023A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 11, 1993 |
| Grant date | Jun 28, 1994 |
| Priority date | — |
| Expiry date | Jun 11, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An outdoor lighting control circuit for operation with a variable input voltage and with an electrical lamp, the circuit including a first resistive impedance element for protecting the circuit from excessive current, and a photosensitive element for presenting a first impedance when actuated by light and a different second impedance in the absence of light. The photosensitive element is electrically in series with the first resistive impedance element, to form a first series combination. An electrical relay in the circuit has contacts for selectively connecting the load to the input voltage and has a relay coil. A second resistive impedance element of the circuit controls the current in the relay coil. The second resistive impedance element is electrically in parallel with the relay coil, to form a first parallel combination. The first parallel combination is electrically in series with the first series combination, all elements being between the input terminals that receive the operating voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.