Harry Ward Leonard
H. Ward Leonard | |
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electrical engineer |
Harry Ward Leonard (February 8, 1861 – February 18, 1915) was an American
Early life and heritage
Harry Ward Leonard was born on February 8, 1861, in
As a student at the Massachusetts Institute of Technology (MIT), Leonard was instrumental in founding the student newspaper, The Tech, and served as the president of the paper’s board of directors. He graduated from MIT in 1883.[1]
Career
After graduating from MIT, Leonard was employed by
While working for Edison, Leonard patented a number of inventions and he continued developing new ideas throughout his career. He was granted patents for more than 100 inventions of electrical distribution and control systems and related equipment.
The Ward Leonard motor control system
The Ward Leonard motor control system was Mr. Leonard’s best known and most lasting invention. It was introduced in about 1891 and soon became the most widely used type of
In a Ward Leonard system, a
Although only technical specialists are likely to be familiar with Ward Leonard systems, many millions of people have ridden in elevators powered by Ward Leonard drives. From the 1920s through the 1980s most electrically driven elevators used Ward Leonard control and many systems remained in use at the beginning of the 21st century.[5]
Many variations of the Ward Leonard system have been implemented, but they have generally continued to be called Ward Leonard systems. H. Ward Leonard and many others have patented auxiliary
Mechanical types of
Sudden death
H. Ward Leonard was an active member of the American Institute of Electrical Engineers, publishing technical papers, attending meetings and making presentations. He died suddenly on February 18, 1915, in New York while attending the annual dinner of the American Institute of Electrical Engineers.[6]
See also
- Booster (electric power)
- Motor-generator
- Rotary transformer
- Ward leonard control
References
Citations
- ^ "The Tech" (PDF). Vol. 36. No. 52. Massachusetts Institute of Technology. 1916-11-22. Retrieved 2006-08-08.
- ^ "Westchester County Archives". Incorporation Records, 1876-1914 -- Personal Name Index -- L-M A-0050 (8), p. 64. Westchester County, New York. 1898-02-19. Retrieved 2006-08-07.
- ISBN 0-07-057746-3.
- ^ Leonard, H. Ward (1891-11-24). "Electrical Transmission of Power patent no. 463,802". United States Patent Office. Archived from the original on 2020-09-22. Retrieved 2006-08-10.
- ^ Kulkarni, A.B. (October 2000). "Energy consumption analysis for geared elevator modernization: upgrade from DC Ward Leonard system to AC vector controlled drive". Conference Record of the 2000 IEEE Industry Applications Conference. Institute of Electrical and Electronics Engineers. pp. vol.4, pp.2066–2070.
- ^ Everett, Jasen M.; Ed. (2006). ""1915." The People's Chronology". Thomson Gale; eNotes.com. Retrieved 2006-08-07.
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General references
- The Editors (November 1989). "Technology for Electrical Components". Power Transmission Design: 25–27.
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has generic name (help) - Staff (December 1971). "Motor Speed Drive Survey". Instruments and Control Systems: 69–70.
- "H. Ward Leonard Dies". The New York Times. February 19, 1915. archives.