Lucien Gaulard
Lucien Gaulard (16 July 1850 – 26 November 1888). Frequently referred to as Lucien Goulard.
Born in Paris.
Gaulard died in an institution (Sainte-Anne Hospital) in Paris, and was said to have lost his reason due to the loss of the patents on his invention.
The above information is condensed from the Wikipedia.
Gaulard and John Dixon Gibbs are often credited as the co-inventors of the AC step-down transformer. The transformer was first demonstrated in 1883 at London's Royal Aquarium. At the time the term "transformer" had not yet been invented, so instead it was referred to as a "secondary generator". Gibbs's role in the invention appears to have been more that of a financial backer and businessman.
Information on an exhibition of Gibbs and Gaulard's transformer in Turin, Italy in 1884 was published in 1885 and caught the attention of George Westinghouse. In the summer of 1885 Westinghouse bought the American rights for Gibbs and Gaulard's design and ordered that several transformers from Gibbs and Gaulard. Westinghouse then asked the engineer William Stanley, Jr. to design an electric lighting system using them. Stanley subsequently greatly improved on Gibbs and Gaulard's design and is often credited in their place.
The above information is condensed from the Wikipedia entry for John Dixon Gibbs.
See also Gaulard-Gibbs.