Sealed Beam

A sealed beam is a type of unitized lamp with a parabolic reflector, one or more filaments, and a glass or polycarbonate lens all permanently attached together and sealed. Originally introduced for road vehicle headlamp service, sealed beams have since been applied elsewhere. Halogen sealed beam lamps have an inbuilt halogen lamp with the filaments contained in a quartz or hard glass envelope.

Sealed beams are technically known as parabolic aluminumized reflector or "PAR" lamps. Round PAR lamp diameter is expressed in non-metric units of measurement equal to one eighth of an inch, so a PAR56 lamp, for example, is 56/8" (i.e., 7 inches) in diameter. Other popular sizes are PAR30, PAR36, PAR38, PAR46, and PAR64. Rectangular PAR lamp size is expressed in millimeters, so a PAR200×142 is 200mm wide and 142mm tall.

Sealed beams are available in a variety of nominal voltage ratings, most commonly 6, 12, 24, 28, 120, and 230 V. The actual operating voltage may differ from the nominal rated voltage; for example, "12 volt" sealed beam headlamps are meant for use in automobiles with typical line voltage of 13.5 to 14.2 with the engine running.

Read more about Sealed BeamAutomotive Headlamps, Aircraft, Building and Stage Lighting, Lighthouses

Other articles related to "beam, beams, sealed beam":

History of Automotive Headlamps - Mechanics
... Dipping" (low beam) headlamps were introduced in 1915 by the Guide Lamp Company, but the 1917 Cadillac system allowed the light to be dipped with a lever inside the car rather than requiring the ... the first modern unit, having the light for both low (dipped) and high (main) beams of a headlamp emitting from a single bulb. 1938 Cadillacs, and their 1954 "Autronic Eye" system automated the selection of high and low beams ...
History of Automotive Headlamps - Design and Style - Headlamp Styling in The United States, 1940–1983
... of state motor vehicle administrators standardised upon a system of two 7 in (178 mm) round sealed beam headlamps on all vehicles – the only system allowed for 17 years ... than two – one high/low and one high-beam 5+3⁄4 in (146 mm) sealed beam on each side – was introduced in 1957 by Cadillac, Chrysler and Nash on some ... These lamps had some photometric advantages, particularly on high beam and permitted more design flexibility ...
Sealed Beam - Lighthouses
... Sealed beam lamp arrays are also in use by modern lighthouses. ...
Cannanore Lighthouse Today
... Today, the light uses modern PRB-42 equipment with 6 volt, 30 watt Type 'C' sealed beam lamps, supplied by Messers J ... On 31 May 2003, the 'C' type sealed beam lamps were replaced by 'D' type sealed beam lamps ...
Yellow Coach Manufacturing Company - Models Produced - P-series (1939-1944)
... frame, improved engine mounts, conventional clutch pedal and sealed beam headlights also includes appearance changes as listed under PG-2505 ... transmission shift, improved frame, improved engine mounts, conventional clutch pedal and sealed beam headlights ... PG-2901 with two-rod transmission shift, and sealed beam headlights, double-wrapped spring eyes and improved double-drag steering link ...

Famous quotes containing the words beam and/or sealed:

    Why beholdest thou the mote that is in thy brother’s eye, but considerest not the beam that is in thine own eye?
    Bible: New Testament Jesus, in Matthew, 7:3.

    From the Sermon on the Mount.

    These things are not inscribed in tablets, not sealed in the folds of papyri, but you hear them clearly from the tongue in a free mouth.
    Aeschylus (525–456 B.C.)