Experimental electrodeless compact fluorescent lamp

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As energy prices soared in the 1970s, General Electric, like other lamp makers, focused research efforts on raising the energy efficiency of electric lamps. One research program conducted by John Anderson at the GE Corporate Research and Development Laboratory in Schenectady, New York, sought to make a small fluorescent lamp that might replace a regular incandescent lamp.
Most fluorescent lamps, large and small, operate by passing an electric current through a gas between two electrodes. The current energizes the gas that in turn radiates ultraviolet (UV) light. The UV is converted to visible light by a coating of phosphors inside the glass envelope of the lamp. Electrodes are responsible for much of the energy lost in a fluorescent lamp and are usually the part of the lamp that fails. Instead of electrodes, Anderson's design used a donut-shaped, ferrite (an iron oxide compound) to generate an electric field. The field energized the gas.
He called his design a Solenoidal Electric Field (SEF) lamp. The one seen here is an experimental unit made around 1978. While the lamp worked in the lab, the electronics to control it were expensive and generated heat that needed to be dissipated. As with other electrodeless lamps, radio-frequency interference was a concern. By the early 1980s GE decided to shelve the SEF lamp and market a miniature metal-halide lamp instead. In the late 1990s, however, GE took advantage of the lower cost and higher capability of electronic components and marketed an electrodeless lamp that built on prior work—including the SEF lamp.
Lamp characteristics: No base. A 1.5" (outside dia.) toroid-shaped ferrite is mounted vertically inside the lamp and held in place by a wire cradle. The conducting wire is insulated with woven nylon and wrapped ten turns around the top of the ferrite. A woven nylon mat is wrapped around the ferrite under the conductor, and another is placed between the conductor and the top-plate of the mount-cradle. A metal lead extends from the bottom of the ferrite into the exhaust-tip where it spirals around a metal cylinder. Tipless, AT-shaped envelope.
Date made
ca 1978
date made
ca. 1978
General Electric Corporate Research & Development Laboratory
Place Made
United States: New York, Schenectady
Physical Description
glass (overall material)
metal (overall material)
ferrite (overall material)
overall: 4 1/4 in x 3 1/4 in; 10.795 cm x 8.255 cm
ID Number
accession number
catalog number
Credit Line
from General Electric Corporate Research & Development Laboratory
See more items in
Work and Industry: Electricity
Industry & Manufacturing
Energy & Power
Data Source
National Museum of American History


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