History of the Alternating Current Transformer

No, despite his claims later in life and their being repeated by gullible journalists and biographers, Nikola Tesla had nothing to do with the invention of the AC transformer. His Tesla coil was a resonant transformer, but it was developed in 1891, well after George Westinghouse and his employee William Stanley patented and began manufacturing transformers for alternating current power distribution.


That ultimately led to:

Wikipedia on William Stanley, Jr.