Low-voltage fluorescent lamps

FLUORESCENT lamps have been developed, simple in design, and operating through suitable ballast from 115- and 230-volt a-c circuits. They are tubular in form, and the fluorescent material is energized by a hot-cathode positive-column electric discharge. Just as a transformer converts one voltage to another, the fluorescent powder adhering to the inner wall of the bulb converts the invisible ultraviolet radiation present in a low-pressure mercury discharge into visible radiation, or light. Recent progress in the development of these lamps has resulted from the gradual increase in knowledge pertaining to hot cathodes, to the production of short-wave ultraviolet, and to the manufacture of efficient fluorescent powders. These advances have been applied in a lamp to produce colored light many times more efficiently than do present light sources. In addition, fluorescence makes possible for the first time an efficient, practicable, low-wattage white light matching daylight in appearance. Much of the development has been concentrated on the electrical characteristics of the lamps, and on the design of efficient ballast equipment. The lamps described are in one of several classes which are under development. In some respects they are experimental and may be changed before being commercialized.