When I lived on Long Island, NY, I was only 17 miles from a place known as Wardenclyffe — -the site of Nikola Tesla’s sole remaining laboratory which housed his massive energy magnifying tower.
This was all funded by J.P. Morgan. I visited that site and it was kind of an eerily silent atmosphere with his laboratory building overgrown by weeds and the concrete base of the energy tower as the only part left of his long-ago demolished masterpiece. That Tower’s purpose was to improve trans-Atlantic communications.
Tesla was an eccentric, but brilliant, scientist born in Croatia in 1856. He is very well known for the development of the Tesla Coil concept (circa 1890), AC motor (circa 1883), Rotating magnetic field (circa 1882), Radio (circa 1897).
Nikola Tesla dreamed of a concept of ‘getting energy from the air’ to power all equipment; this was an early Energy Harvesting concept. His ideas about RF/Wireless Power and Alternating Current (AC) systems to transmit energy led him to build his tower at Wardenclyffe, which was to be a wireless power generator as well as a communication system.
This scientist conceived the idea that his concepts could power electric vehicles and flying dirigibles. Tesla believed that fossil fuels such as petroleum would not be sustainable for very long! This was in 1901!
Tesla commented, “Night will not interrupt the flow of the new power supply. The disappearance of the sun below the horizon will not shut it off.”
Fast-forward to the 21st century in which we now live and we find a growing industry evolving from Tesla’s concepts (And most people thought Nikola Tesla to be crazy!).
We now have such things as a Sonicare electric toothbrush that charges via inductive power (I have one myself). Electric vehicle (EV) chargers are even using various wireless protocols that are capable of charging the vehicle’s batteries.
The standard AC power supply of 110V or 220V can be converted into high frequency AC which gets supplied to the wireless transmitter coil which then creates a magnetic field that powers a receiver coil in the EV which in turn produces an AC power output to charge the EV.
One of the best places I know of to learn about efficient wireless power charging is Efficient Power Conversion’s (EPC) website on Wireless Power. Some of the most informative textbooks on Wireless Power have been authored by EPC engineers and are listed here.
EPC designs and products GaN power transistors which are the power element used in these designs. These power transistors are the most efficient in the industry and they help create the smallest physical designs in the industry.
One of the most challenging and intriguing applications of wireless power transfer technology is the EV. Wireless charging of an EV has essentially the same charging technique of wireless charging a cell phone on a Starbucks mat in some of their stores. The latest area for this is a select group of stores in the Boston area.
With an EV, the driver positions the car in the proximity of a floor mat or embedded system in the floor that contains the wireless power transmitting circuit. The distance between that and the wireless receiver coil in the EV is set to optimize the efficiency of magnetic wireless flux transferring the power from the source to the receiver. No cables necessary and it’s immune to dirt and water.
BMW and Tesla have their own wireless charging facilities spread out in many areas. Wireless charging providers are also Qualcomm, WiTricity, Nissan, Toyota, and Plugless.
1 Nikola Tesla’s, Dream Realized Wireless power energy harvesting, By William Lumpkins, IEEE Consumer Electronics Magazine, January 2014
3 Get Electric Vehicle website