New lighting inventions occasionally appear from unexpected directions. The development of this microwave-powered lamp provides a case in point. In 1990 Fusion Systems was a small company with a successful, highly specialized product, an innovative ultraviolet (UV) industrial lighting system powered by microwaves.
Discharge lamps typically use electrodes to support an electric arc. Tungsten electrodes are most common, so materials that might erode tungsten can't be used in the lamp and care must be taken to not melt the electrodes. Fusion's lamp side-stepped this problem by eliminating electrodes entirely. Microwave energy from an external source energized the lamp. This opened the way for experiments with non-traditional materials, including sulfur.
During the 1980s engineer Michael Ury, physicist Charles Wood, and their colleagues experimented several times with adapting their UV system to produce visible light without success. In 1990, they tried placing sulfur in a spherical bulb instead of a linear tube. Sulfur could give a good quality light, but did not work well in the linear tube. Other elements only gave marginal results in the spherical bulb. But when they tested sulfur in the spherical lamp they found what they hoped for: lots of good visible light with little invisible UV or infrared rays.
They began setting up "crude" lamps like this one (one of the first ten according to Ury) in order to learn more about the new light source. In the mid-1990s Fusion began trying to sell their sulfur bulbs with limited success. The lamp rotated at 20,000 rpm so that the temperature stayed even over the surface, and a fan was needed for cooling. The fan and spin motor made noise and reduced energy efficiency of the total system. Then they found that the bulbs lasted longer than the magnetrons used to generate the microwaves that powered them. Finding inexpensive magnetrons proved too difficult, and the company stopped selling the product in 2002.
Lamp characteristics: A quartz stem with notch near the bottom serves as the base. The notch locks the lamp into its fixture. The sphere has an argon gas filling, and the yellow material is sulfur condensed on the inner lamp wall. The pattern of condensation indicates lamp was burned base-down. Tipless, G-shaped quartz envelope.
The development of practical fluorescent lamps took decades, and many researchers contributed. Julius Plucker and Heinrich Geissler made glowing glass tubes in the 1850s, about the time George Stokes discovered that invisible ultraviolet light made some materials glow or "fluoresce." Alexandre Edmond Becquerel put fluorescent materials in a Geissler tube in 1859, though his tubes did not last long. Carbon dioxide-filled tubes by D. McFarlan Moore and mercury vapor tubes by Peter Cooper Hewitt around 1900 gave practical experience with gas-filled, discharge lamps and inspired the neon tubes of Georges Claude.
In 1926 Friedrich Meyer, Hans Spanner, and Edmund Germer of Germany patented an enclosed glass tube containing mercury vapor, electrodes at either end, and a coating of fluorescent powders called phosphors. This incorporated all of the features we see in modern fluorescent tubes, but their employer did not pursue development. William Enfield of General Electric saw phosphor-coated neon tubes in France in the early 1930s, and heard that European researchers were developing a fluorescent lamp. An especially urgent 1934 letter from a consultant, Nobel-laureate Arthur Compton, coming on the heels of European breakthroughs in low-pressure sodium and high-pressure mercury lamps, spurred both GE and its licensee Westinghouse into combined action.
Enfield created a team led by George Inman, and by the end of 1934 they made several working fluorescent lamps, including the one seen here. To save time, the team adopted the design of an existing tubular incandescent lamp in order to make use of available production equipment and lamp parts. Speed was important. In addition to European competitors, American companies like Sylvania were also working on fluorescents. A second GE group under Philip Pritchard worked on production equipment. Other GE groups in Schenectady and in Ft. Wayne assisted in developing ballasts and resolving problems of circuit design.
In 1936 GE and Westinghouse demonstrated the new lamp to the U.S. Navy (that lamp is in the Smithsonian's collection). The public finally saw fluorescent lamps in 1939 at both the New York World's Fair and the Golden Gate Exposition in San Francisco. These early lamps gave twice the energy efficiency of the best incandescent designs. Production of fluorescent lamps, slow at first, soon soared as millions were installed in factories making equipment for the American military during World War 2.
Lamp characteristics: Double-ended without bases. Flat presses with an exhaust tip near one press. A tungsten electrode, CC-6 configuration coated with emitter, is set at either end. A mercury pellet is loose inside the lamp. The clear T-7 glass envelope has a phosphor coating covering about 3 inches (8 cm) of the lamp near the center.
General Electric Corporate Research & Development Laboratory
ID Number
1998.0050.16
accession number
1998.0050
catalog number
1998.0050.16
Description
As energy prices soared in the 1970s, lamp makers focused research efforts on raising the energy efficiency of electric lamps. A great deal of effort by many researchers went into designing small fluorescent lamps that might replace a regular incandescent lamp. These efforts led to modern compact fluorescent lamps that use bent or connected tubes, but many other designs were tried. This experimental "partition lamp" from 1978 shows one such design.
Soon after the 1939 introduction of linear fluorescent lamps, inventors began receiving patents for smaller lamps. But they found that the small designs suffered from low energy efficiency and a short life-span. Further research revealed that energy efficiency in fluorescent lamps depends in part on the distance the electric current travels between the two electrodes, called the arc path. A long arc path is more efficient than a short arc path. That's why fluorescent tubes in stores and factories are usually 8 feet (almost 3 meters) long.
Inventors in the 1970s tried many ways of putting a long arc path into a small lamp. In this case there are thin glass walls inside the lamp, dividing it into four chambers. Each chamber is connected in such a way that the electric current travels the length of the lamp four times when moving from one electrode to the other. So the arc path is actually four times longer than the lamp itself, raising the energy efficiency of the lamp. This unit was made by General Electric for experiments on the concept, though other makers were also working on partition lamps.
While the partition design works, it proved to be expensive to manufacture and most lamp makers decided to use thin tubes that could be easily bent and folded while being made.
Lamp characteristics: No base. Two stem assemblies each have tungsten electrodes in a CCC-6 configuration with emitter. Welded connectors, 3-piece leads with lower leads made of stranded wire. Bottom-tipped, T-shaped envelope with internal glass partition that separates the internal space into four connected chambers. Partition is made of two pieces of interlocked glass and is not sealed into the envelope. All glass is clear. No phosphors were used since the experimenter wanted to study the arc path.
General Electric Corporate Research & Development Laboratory
ID Number
1998.0050.07
accession number
1998.0050
catalog number
1998.0050.07
Description
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.
In the mid-1990s Fusion Lighting began selling a microwave-powered lighting system. The small, spherical bulbs contained a small amount of the element sulfur that gave a large amount of good quality light when energized by microwaves. Company researchers began investigating other materials to learn more about their new light source and perhaps to discover another saleable product.
The lamp is from one of those follow-on experiments and contains a mix of sulfur and another element, selenium. Both elements have related properties. Chemists refer to them as Group VI elements since they appear in the same column of the Periodic Table. Fusion researchers felt that these related elements might work well together in the new system. The company donated two other sulfur-selenium lamps from the same experiment that contain mixtures with differing ratios of the two elements.
Lamp characteristics: A quartz stem with a notched metal sleeve near the bottom serves as the base. The notch locks the lamp into its fixture. The sphere has an argon gas filling with a tiny amount of Krypton-85 to help start the discharge. The orange material condensed on the inner wall is an equal mix of sulfur and selenium. The pattern of condensation indicates lamp was burned vertically. Tipless, G-shaped quartz envelope.
Electricity pioneer Lewis Latimer drew this component of an arc lamp, an early type of electric light, for the U.S. Electric Lighting Company in 1880.
The son of escaped slaves and a Civil War veteran at age sixteen, Latimer trained himself as a draftsman. His technical and artistic skills earned him jobs with Alexander Graham Bell and Thomas Edison, among others. An inventor in his own right, Latimer received numerous patents and was a renowned industry expert on incandescent lighting.
Telegraph message, printed in Morse code, transcribed and signed by Samuel F. B. Morse. This message was transmitted from Baltimore, Maryland, to Washington, D.C., over the nation's first long-distance telegraph line.
In 1843, Congress allocated $30,000 for Morse (1791-1872) to build an electric telegraph line between Washington and Baltimore. Morse and his partner, Alfred Vail (1807-1859), completed the forty-mile line in May 1844. For the first transmissions, they used a quotation from the Bible, Numbers 23:23: "What hath God wrought," suggested by Annie G. Ellsworth (1826-1900), daughter of Patent Commissioner Henry L. Ellsworth (1791-1858) who was present at the event on 24 May. Morse, in the Capitol, sent the message to Vail at the B&O Railroad's Pratt Street Station in Baltimore. Vail then sent a return message confirming the message he had received.
The original message transmitted by Morse from Washington to Baltimore, dated 24 May 1844, is in the collections of the Library of Congress. The original confirmation message from Vail to Morse is in the collections of the Connecticut Historical Society.
This tape, dated 25 May, is a personal souvenir transmitted by Vail in Baltimore to Morse in Washington the day following the inaugural transmissions. The handwriting on the tape is that of Morse himself. Found in Morse’s papers after his death the tape was donated to the Smithsonian in 1900 by his son Edward, where it has been displayed in many exhibitions.
This bicycle’s welded steel rear fork was created using Elihu Thomson’s electric welding apparatus (see object number MC*181724). Welding samples demonstrated the potential industrial applications of electric welding, and illustrations of these samples were published in journals, brochures, and advertisements. Elihu Thomson’s invention of electric welding in 1885 resulted in numerous industrial applications including the manufacture of automobile parts, tools, screws, ball bearings, and wire lines. Thomson’s welding apparatus pressed two pieces of metal together while an electric current ran through the metal. Resistance to the current at the contact point between the metal pieces created heat and welded the metals together.
Scientist and inventor Elihu Thomson (1853-1937) played a prominent role in the industrialization and electrification of America with over 700 patents in his name. His inventions and patents helped change the nature of industry in the United States and included the “uniflow” steam engine, automobile muffler, producing fused quartz, stereoscopic x-ray pictures, electric arc lamps, lightning arrestors, and perhaps most notably—the process of electrical welding. Thomson and partner Edwin Houston established a variety of companies to manage his industrial interests. In 1892, his Thomson-Houston Electric Company merged with the Edison Electric Company to form General Electric.
This bicycle’s welded steel tapered head tube was created using Elihu Thomson’s electric welding apparatus (see object number MC*181724). Welding samples demonstrated the potential industrial applications of electric welding, and illustrations of these samples were published in journals, brochures, and advertisements. Elihu Thomson’s invention of electric welding in 1885 resulted in numerous industrial applications including the manufacture of automobile parts, tools, screws, ball bearings, and wire lines. Thomson’s welding apparatus pressed two pieces of metal together while an electric current ran through the metal. Resistance to the current at the contact point between the metal pieces created heat and welded the metals together.
Scientist and inventor Elihu Thomson (1853-1937) played a prominent role in the industrialization and electrification of America with over 700 patents in his name. His inventions and patents helped change the nature of industry in the United States and included the “uniflow” steam engine, automobile muffler, producing fused quartz, stereoscopic x-ray pictures, electric arc lamps, lightning arrestors, and perhaps most notably—the process of electrical welding. Thomson and partner Edwin Houston established the Thomson-Houston Electric Company in 1883. In 1892 Thomson-Houston merged with the Edison Electric Company to form General Electric.
This bicycle’s welded steel seat post was created using Elihu Thomson’s electric welding apparatus (see object number MC*181724). Welding samples demonstrated the potential industrial applications of electric welding, and illustrations of these samples were published in journals, brochures, and advertisements. Elihu Thomson’s invention of electric welding in 1885 resulted in numerous industrial applications including the manufacture of automobile parts, tools, screws, ball bearings, and wire lines. Thomson’s welding apparatus pressed two pieces of metal together while an electric current ran through the metal. Resistance to the current at the contact point between the metal pieces created heat and welded the metals together.
Scientist and inventor Elihu Thomson (1853-1937) played a prominent role in the industrialization and electrification of America with over 700 patents in his name. His inventions and patents helped change the nature of industry in the United States and included the “uniflow” steam engine, automobile muffler, producing fused quartz, stereoscopic x-ray pictures, electric arc lamps, lightning arrestors, and perhaps most notably—the process of electrical welding. Thomson and partner Edwin Houston established the Thomson-Houston Electric Company in 1883. In 1892 Thomson-Houston merged with the Edison Electric Company to form General Electric.
This bicycle’s welded steel head post was created using Elihu Thomson’s electric welding apparatus (see object number MC*181724). Welding samples demonstrated the potential industrial applications of electric welding, and illustrations of these samples were published in journals, brochures, and advertisements. Elihu Thomson’s invention of electric welding in 1885 resulted in numerous industrial applications including the manufacture of automobile parts, tools, screws, ball bearings, and wire lines. Thomson’s welding apparatus pressed two pieces of metal together while an electric current ran through the metal. Resistance to the current at the contact point between the metal pieces created heat and welded the metals together.
Scientist and inventor Elihu Thomson (1853-1937) played a prominent role in the industrialization and electrification of America with over 700 patents in his name. His inventions and patents helped change the nature of industry in the United States and included the “uniflow” steam engine, automobile muffler, producing fused quartz, stereoscopic x-ray pictures, electric arc lamps, lightning arrestors, and perhaps most notably—the process of electrical welding. Thomson and partner Edwin Houston established a variety of companies to manage his industrial interests. In 1892, his Thomson-Houston Electric Company merged with the Edison Electric Company to form General Electric.
Original switch key put in on introduction of the second dynamo, November, 1881. A wooden knife switch mounted on a wooden base. Four binding posts. Used in the Hinds-Ketchum printing plant as part of the first commercial installation of the Edison lighting system.
Original safety plugs put in on system in December, 1881. Prior to this a small section of lead wire had been soldered into the trunk line and there were no safety plugs [fuses] on any of the main lines to the lamps. Used in the Hinds-Ketchum printing plant as part of the first commercial installation of the Edison lighting system
Thomas Edison used this carbon-filament bulb in the first public demonstration of his most famous invention, the first practical electric incandescent lamp, which took place at his Menlo Park, New Jersey, laboratory on New Year's Eve, 1879.
As the quintessential American inventor-hero, Edison personified the ideal of the hardworking self-made man. He received a record 1,093 patents and became a skilled entrepreneur. Though occasionally unsuccessful, Edison and his team developed many practical devices in his "invention factory," and fostered faith in technological progress.
This bicycle’s welded steel top tube was created using Elihu Thomson’s electric welding apparatus (see object number MC*181724). Welding samples demonstrated potential industrial applications of electric welding, and illustrations of these samples were published in journals, brochures, and advertisements. Elihu Thomson’s invention of electric welding in 1885 resulted in numerous applications including the manufacture of automobile parts, tools, screws, ball bearings, and wire lines. Thomson’s welding apparatus passed an electric current through two pieces of metal pressed together. Resistance to the current at the contact point between the metal pieces created heat and welded the metals together.
Scientist and inventor Elihu Thomson (1853-1937) played a prominent role in the industrialization and electrification of America with over 700 patents in his name. His inventions and patents helped change the nature of industry in the United States and included the “uniflow” steam engine, automobile muffler, producing fused quartz, stereoscopic x-ray pictures, electric arc lamps, lightning arrestors, and perhaps most notably—the process of electrical welding. Thomson and partner Edwin Houston established the Thomson-Houston Electric Company in 1883. In 1892 Thomson-Houston merged with the Edison Electric Company to form General Electric.
This bicycle’s welded steel crank hanger was created using Elihu Thomson’s electric welding apparatus (see object number MC*181724). Welding samples demonstrated the potential industrial applications of electric welding, and illustrations of these samples were published in journals, brochures, and advertisements. Elihu Thomson’s invention of electric welding in 1885 resulted in numerous industrial applications including the manufacture of automobile parts, tools, screws, ball bearings, and wire lines. Thomson’s welding apparatus pressed two pieces of metal together while an electric current ran through the metal. Resistance to the current at the contact point between the metal pieces created heat and welded the metals together.
Scientist and inventor Elihu Thomson (1853-1937) played a prominent role in the industrialization and electrification of America with over 700 patents in his name. His inventions and patents helped change the nature of industry in the United States and included the “uniflow” steam engine, automobile muffler, producing fused quartz, stereoscopic x-ray pictures, electric arc lamps, lightning arrestors, and perhaps most notably—the process of electrical welding. Thomson and partner Edwin Houston established a variety of companies to manage his industrial interests. In 1892, his Thomson-Houston Electric Company merged with the Edison Electric Company to form General Electric.