Brevetti

Trasformatore, Nikola Tesla, (1890):  patent 433,702 electrical transformer

Radio frequency transformer and coil form, Willyard, Leslie A.
Taegtstroem V, Ingemar R., (1956): United States Patent 2751563 (pdf)

Transformer, Tabuchi Electric Co, (1995): United States Patent 5696477

Transformer, Hitachi Industrial Equipment Systems Co., Ltd., Tokyo, (2006): patent US 8,198,973 B2

Docking station for a transformer, ABB Technology AG, Zurich, (2007): patent US 8,198,966 B2

 Trasformatori risonanti, Issa Messer Tobias, (2008): patent 61004373 Resonant transformer systems and methods of use