English: Diagram by Serbian-American inventor Nikola Tesla from about 1893 illustrating how his wireless power transmission system was supposed to work. At top is a simplified circuit diagram of the system. The transmitter (left) consists of a grounded high voltage generator (consisting of a Tesla coil) driving an elevated capacitive plate. The receiver (right) consists of an electrical load connected between a similar plate and ground. The transmitter and receiver have tuned circuits which are tuned to resonance. At bottom is a mechanical analogy showing how he believed the system would work, consisting of two tuning forks coupled through a hydraulic fluid. Tesla saw the charge of the Earth as similar to a fluid. The oscillating potential (voltage) applied to the ground by the transmitter was analogous to an oscillating pressure applied by a tuning fork. The oscillating voltage would be applied to the receiver, causing resonant currents in the receiving tuned circuit. Tesla was able to transmit power short distances (up to about 100 ft) by this technique, but his efforts at long distance wireless transmission failed.