[DOC] [TLE] History of Transformers - Edison Tech Center [PAR] Engineering Resources. ... A: A transformer is is a device that transfers electrical 
energy from one circuit to ... A transformer can be used to convert AC power to 
DC power. ... William Stanley (USA) ... William Stanley's First Transformer built in 
1885. ... Nicholas Callan of Maynooth College, Ireland invents the induction coil. [DOC] [TLE] George Westinghouse - Wikipedia [PAR] George Westinghouse, Jr. (October 6, 1846  March 12, 1914) was an American 
entrepreneur and engineer who invented ... At age 21 he invented a "car replacer
", a device to guide derailed railroad cars back onto ... In 1884 he started 
developing his own DC lighting system and hired physicist William Stanley to 
work on it. [DOC] [TLE] War of Currents - Wikipedia [PAR] The War of Currents was a series of events surrounding the introduction of 
competing electric ... In June of that year a New York electrical engineer named 
Harold P. Brown .... Ott Blthy also invented the first AC electricity meter. ... in 
1884 when he started to develop a DC system and hired William Stanley, Jr. to 
work on it. [DOC] [TLE] Alternating current - Wikipedia [PAR] Alternating current (AC), is an electric current in which the flow of electric charge 
periodically ... The abbreviations AC and DC are often used to mean simply 
alternating and direct, ...... Ott Blthy also invented the first AC electricity meter. 
... In the US William Stanley, Jr. designed one of the first practical devices to 
transfer AC... [DOC] [TLE] William Stanley Jr. - Wikipedia [PAR] William Stanley Jr. (November 28, 1858  May 14, 1916) was an American 
physicist born in Brooklyn, New York. In his career, he obtained 129 patents 
covering a variety of electric devices. ... Shortly thereafter, George Westinghouse 
hired Stanley as his chief engineer at his Pittsburgh factory. In 1885, Stanley built 
the first... [DOC] [TLE] War of the Currents [PAR] the earliest sources of continuous electrical energy were batteriesDC devices. 
... Courtesy Nikola Tesla Museum. DC vs. AC. Direct current (DC) electricity ... 
American inventor Thomas Edison also faced similar ... Thomas Davenport 
invented the commutator, .... William Stanley to improve the primitive design into 
one. [DOC] [TLE] Initial Tesla Polyphase / "Three-Phase" Alternating-Current Systems ... [PAR] Jul 10, 2015 ... Inventor Thomas A. Edison led in the development of the DC electric motor and 
.... relay invented by America's Joseph Henry, AC electric power could be sent ... 
Westinghouse, who had originally employed William Stanley, Jr. to develop ... in 
developing the AC systems with electrical engineer Philip Lange,... [DOC] [TLE] William Stanley - Engineering and Technology History Wiki [PAR] Birthdate: 1858/11/22; Birthplace: Brooklyn, NY, USA; Death date: 1916/05/14 ... 
William Stanley was born in Brooklyn, New York, 22 November 1858, the son ... 
He entered Yale the year Thomas Edison invented the incandescent electric ... 
The prevailing power system of the day was the Edison Direct Current (dc) 
system. [DOC] [TLE] Lucien Gaulard - Revolvy [PAR] In 1885, William Stanley, Jr. built the first practical transformer based on Gaulard 
... invented devices for the transmission of alternating current electrical energy. ... 
a device in London in 1881 and then sold the idea to the American company .... 
the conversion between AC and DC power and the development of specialized... [DOC] [TLE] The Day They Turned the Falls On: The Invention of the Universal ... [PAR] The gargantuan electrical power production facilities--the largest in the ... Frank J. 
Sprague, a U.S. Naval Academy graduate, invented the DC motor. After naval ... 
AC, on the other hand, had the transformer for raising or lowering voltage. ... An 
effective transformer was developed in 1886 by William Stanley, then working for
... [DOC] [TLE] Dismantling of our Power Industry Infrastructure | DaVinci Institute ... [PAR] Feb 10, 2012 ... Edison invented the first electric meter to bill customers for the ... Westinghouse 
put together a team run by William Stanley to explore ways ... a long-range

Question: American electrical engineer William Stanley invents this device for changing energy from AC to DC
Answer: transformer