Accession Number : ADA297734

Title :   Light Emitting Diode (LED) Red Buoy Light.

Descriptive Note : Final rept.,

Corporate Author : COAST GUARD RESEARCH AND DEVELOPMENT CENTER GROTON CT

Personal Author(s) : Roberts, Bruce R.

PDF Url : ADA297734

Report Date : JUL 1995

Pagination or Media Count : 46

Abstract : At the present time, the U.S. Coast Guard (USOG) employs the 155MM lantern as the standard equipment used on lighted buoys and many small fixed structures. This lantern uses a tungsten lamp as a light source and a colored lens to filter out the unwanted color when green or red lights are desired. This method of obtaining colored light is inefficient. A prior Research and Development Center effort developed a green direct emitting fluorescent light but failed to deliver a useful red light. This Research Associate Project was undertaken to investigate the use of Light Emitting Diodes (LEDs) as a possible red minor aids-to-navigation light. It was found that a small LED package mounted in a circle with a plastic thin film Fresnel lens was the preferred design. A prototype of 120 LEDs mounted in the above configuration was able to provide a 4-mile nominal range light. This is the most common range light presently in use on buoys. The low cost, high reliability and long life of LEDs are convincing reasons to pursue further efforts in this area. Other possible advantages of LED usage are the ability to design the LEDs to a package that allows the passage of wires and/or supports to the top of the buoy. This can be critical when several apparatuses need to be at the top of the buoy. Finally, the ability to flash LEDs at a very fast rate could allow the Coast Guard to monitor the status of buoys with an optical receiver, while the mariner would perceive the light as being continuous.

Descriptors :   *MARKER LIGHTS, *LIGHT EMITTING DIODES, *BUOYS, OPTICAL EQUIPMENT, HIGH RATE, LOW COSTS, MONITORING, RED(COLOR), LIGHT, LIGHT SOURCES, RECEIVERS, LONG LIFE, TUNGSTEN, LENSES, HIGH RELIABILITY, NAVIGATIONAL AIDS, COAST GUARD, FLASHES, INCANDESCENT LAMPS.

Subject Categories : Electrical and Electronic Equipment
      Air Condition, Heating, Lighting & Ventilating
      Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE