Nikola Tesla British Patent 20,981 - Improvements Relating to the Production, Regulation, and Utilization of Electric Currents of High Frequency, and to Apparatus Therefor
Nikola Tesla German Patent 93255 - Circuit Controller for Converting Currents with a Low Number of Turns into Currents with a High Number of Turns by Means of Capacitor Discharges
Nikola Tesla German Patent 99173 - Device for Obtaining High Frequency Currents from Direct Currents through Capacitor Discharges
Nikola Tesla British Patent 24,421 - Improvements in Systems for the Transmission of Electrical Energy and Apparatus for Use Therein