Method and device to emulate a railway searchlight signal with light emitting diodes
US6642666B1 · kind B1 · utility
99Cited by
14References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 20, 2000 |
| Grant date | Nov 4, 2003 |
| Priority date | — |
| Expiry date | Apr 20, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S362/802
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A railway searchlight signal uses a printed circuit board populated by three arrays (green, red and yellow) of LEDs. The LEDs are lit by a standard color light power supply unit (PSU). As only one array of LEDs is lit at a time, an interface between the PSU and the LEDs is provided to select which LED array to couple with the PSU. External repeater contacts provide information on which aspect is displayed. This searchlight system design is failsafe in that no single failure of a component will produce a less restrictive aspect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.