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1947-48 Theatre Catalog, 6th Edition, Page 324 (310)

1947-48 Theatre Catalog, 6th Edition
1947-48 Theatre Catalog
1947-48 Theatre Catalog, 6th Edition, Page 324
Page 324

1947-48 Theatre Catalog, 6th Edition, Page 324

The New Circlarc Lamp for Lounge Lighting

Decorative Illumination for Public Areas Made Possible by the Half-Circle Design

With the advent of the newly standardized half-circle fluorescent lamp, known as the Circlarc, manufacturers have broken with the traditions of the past and now provide a production lamp that can be incorporated in bare lamp installations to provide a flowing pattern of light on walls or ceilings. The half-circle design also releases the architect or lighting designer from many of the restrictions imposed by straight tubes or the full-circle lamp known as the Circline. It is too early now to predict the extent to which this new halfcircle lamp will be used in theatre lighting but there is little doubt that this field of application will be one of the more important ones in which it is applied.

The 18-watt, 12-inch T-8 Circlarc fluorescent lamp is a curved fluorescent lamp made in the form of a half circle 12 inches in diameter. Used singly or in multiple arrangements, it provides a flexibility of application not obtainable with the full-circle lamp. The are stream of each lamp is short so it may be operated directly from the 110-125-volt a.c. lighting circuit with a small low cost choke as a ballast. Also, the semicircular shape makes it possible to obtain, with a curved fluorescent lamp, the advantages of mass production machinery previously available only with straight tube lamps.

The 18-watt Circlarc lamp operates on a simple reactor type ballast with the regular manual or the FS-2 glow switch starter used for 15- and 20-watt standard fluorescent lamps. Ballast used with the 18-watt Circlarc lamp should be suitable to carry the 0.380 operating amperes without overheating.

DETAIL DRAWING oi the Westinghouse lB-watt Circlarc fluorescent lamp is given at the left. with the right-hand drawing showing how two of the The lamp is in the form

lamps can be joined to term a circle of light.


W'Pslinghouse Electric Corporation

The Circlarc base pins are located at 45 degrees to the plane of the lamp which allows the pins of the two opposing lamp bases to overlap and reduce the thickness of a two-lamp holder to a minimum. Holders should provide good electrical contact with the pin receptacles arranged to float laterally about 1/3, inch so as to allow for the lamp manufacturing tolerances in diameter required.

Pattern and Built-in Lighting

The Circlarc lamp provides a fluorescent shape that is badly needed for new type lighting throughout the theatre. For example, this semi-curcular lamp can be used to form a pattern of light on the ceiling and walls and, in warm climates, on the marquee and the theatre sign. Built-in lights for the niche over the water fountain, and arch of light over the ticket window, pedestal lighting beneath or above flowers or statuettes and a diadem of light over small exhibits such as costume jewelry and the like, all represent new and interesting uses of fluorescent lamps which require a semiecircular shape of lamp.

Pinup type wall fixtures with the half circle lamp in the horizontal position extending out from the wall provide downward or upward light Where needed on or near the wall. For example, beneath a small picture the Circlarc is better than a straight tube against the wall because the center of the luminous tube is automatically extended from the wall

by the graceful curve of the fixture and this makes it possible to throw a greater intensity of light to the top of the picture. Similarly, where a wall fixture is inverted to throw light downward this provides and excellent illuminant for growing plants or vases of flowers mounted on tables or against the wall in the lobby or elsewhere in the theatre building.

Naturally, appearance of lighting equipment is of great importance in the theatre. Aside from the technical advantages of the Circlarc lamp, there is also the basic fact that the curved form is interesting and attractive in contrast to the straight rod-like shapes of most standard fluorescent lamps in general use today. Where single lamps are used in desk, wall and other types of fixtures, this curved shape is perhaps the most important contribution offered by the new Circlarc lamp.

Simplified Maintenance

The half-circle lamp makes replace ment of burnouts a simple and practical operation even in fixtures using more than one complete circle of fluorescent tubing. Such relatively elaborate units are commonly required in large areas as theatre buildings where a single Circline lamp would be inadequate. Two of these tubes form a complete circle and produce comparable lighting results to the Circline lamp. A circle of light built up with two Circlarcs can be taken apart and a burned out lamp readily replaced whereas it is difficult to relamp a Circline fixture using more than one lamp since these ring shaped lamps cannot be threaded through one another. It is this flexibility in the use of the

it may be operated directly from the llO-lZS-volt the. lighting circuit with a small. low-cost choke as a ballast. The base pins are located at 45 degrees to the plane of the lamp, allowing two opposing lamps to over.

of a half circle 12 inches in diameter. The are stream is so short that lap. The right drawing also shows the required ballast connections.

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1947-48 Theatre Catalog, 6th Edition, Page 324