Energy & Power
The Museum's collections on energy and power illuminate the role of fire, steam, wind, water, electricity, and the atom in the nation's history. The artifacts include wood-burning stoves, water turbines, and windmills, as well as steam, gas, and diesel engines. Oil-exploration and coal-mining equipment form part of these collections, along with a computer that controlled a power plant and even bubble chambers—a tool of physicists to study protons, electrons, and other charged particles.
A special strength of the collections lies in objects related to the history of electrical power, including generators, batteries, cables, transformers, and early photovoltaic cells. A group of Thomas Edison's earliest light bulbs are a precious treasure. Hundreds of other objects represent the innumerable uses of electricity, from streetlights and railway signals to microwave ovens and satellite equipment.
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Thomson DC Generator
- Description
- This model of a direct-current generator was designed by Elihu Thomson to produce a constant voltage. It could also be used as a motor that would maintain a constant speed. It came to the Smithsonian from the U. S. Patent Office, representing patent number 333,573, issued to Thomson on January 5, 1886. The patent itself indicates that no model was submitted (which is not surprising since by that time models were not required), and this example was probably given to the Patent Office at a slightly later date for display purposes.
- Thomson and Edwin Houston were school teachers in Philadelphia in the 1870s when they formed a partnership (the Thomson-Houston Company) to enter the new and competitive arc-lighting field. They produced a number of successful generators, motors, meters, and lighting devices. Most of their system employed alternating current, which was as good as direct current for lighting. With the development of the transformer in the mid-1880s, AC systems assumed added importance because electricity generated at a low voltage could now be converted to high voltage for more efficient transmission and then converted back to safer low voltage for use by consumers. But electro-chemical applications (like plating) required DC generators, and, until the invention of a practical AC motor by Nikola Tesla at the end of the 1880s, street railways depended on DC.
- Thomson-Houston merged with Edison's company in 1892 to form General Electric.
- See US Patent # 333573, Dynamo Electric Machine, issued 5 January 1886, to Elihu Thomson. Claim: "A design with spherical armature and round-type frame to obtain a dynamo-electric machine capable of furnishing a constant potential; or an electric motor capable of maintaining a constant speed." No extant maker's markings. This machine has a revolving circular armature with pulley wheel on one end of shaft and adjustable brushes at the other. Field magnets are supported inside the frame.
- Location
- Currently not on view
- Date made
- 1886
- patent date
- 1886-01-05
- associated person
- Thomson, Elihu
- associated company
- Thomson-Houston Electric Company
- maker
- Thomson, Elihu
- ID Number
- EM.252663
- catalog number
- 252663
- patent number
- 333573
- accession number
- 49064
- Data Source
- National Museum of American History
