Experimental "Magnetic Arc-Spreading" compact fluorescent lamp
date: label: Date made
content: ca 1978
label: date made
content: ca. 1978
name: label: maker
content: General Electric Corporate Research & Development Laboratory
label: inventor
content: Spellman High Voltage Electronics Corp.
notes: label: Description
content: The energy crises of the 1970s inspired inventors to try novel ideas for new light bulbs. One of the more unusual designs emerged from the drawing board of Manhattan Project veteran Leo Gross. Supported by Merrill Skeist at Spellman High Voltage Electronics Corporation, Gross designed a compact fluorescent lamp that he called a "magnetic arc spreader" (MAS).
label: Description
content: The design took advantage of a fundamental aspect of electro-magnetism known since the early 1800s. When a current flows through a coil of wire, it produces a magnetic field. The arc discharge that travels between the electrodes of a fluorescent lamp can be affected by the presence of such a field. In the center of the MAS lamp seen here there is a copper coil. Current moving through the coil creates a magnetic field that spreads out the electrical arc within the lamp. The expanded arc energizes phosphor throughout the lamp's entire length.
label: Description
content: The concept was tested at Lawrence Berkeley Laboratory, and General Electric became interested. In 1978 GE purchased a one-year license from Spellman in order to conduct further tests but determined that the necessary glasswork would make the lamp too expensive for commercial production. GE donated one of their test lamps to the Smithsonian in 1998—the only known surviving example of this experimental design.
label: Description
content: Lamp characteristics: No base. Two stranded lead-wires extend about 2" from either end, and each end has one lead wire encased in a glass insulating tube. Two coiled tungsten electrodes are mounted in a hollow cylindrical envelope. The exhaust tip is near one set of leads, and the envelope has an internal phosphor coating. A coil of bare copper wire held together with black string is inserted into the center of the envelope. A current passing thru this coil spreads the arc between electrodes so that more of the phosphor is activated.
place: label: Place Made
content: United States: New York, Hicksville
setName: label: See more items in
content: Work and Industry: Electricity
label: See more items in
content: Energy & Power
label: Exhibition
content: Lighting a Revolution
label: Exhibition Location
content: National Museum of American History
publisher: label: Related Publication
content: Gross, Leo; Skeist, S. Merrill. Feasibility Claimed for Handy Fluorescent
creditLine: label: Credit Line
content: from General Electric Corporate Research & Development Laboratory
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1998.0050.15
label: accession number
content: 1998.0050
label: catalog number
content: 1998.0050.15
objectType: label: Object Name
content: discharge lamp
label: Other Terms
content: discharge lamp; Fluorescent
physicalDescription: label: Physical Description
content: glass (overall material)
label: Physical Description
content: copper (overall material)
label: Physical Description
content: tungsten (overall material)
label: Measurements
content: overall: 8 3/4 in x 3 in; 22.225 cm x 7.62 cm