detest power cords and cables for my various smart devices and domestic appliances. Why is it that almost every device seems to require a different cable and fitting? Why is it that modern designers produce aesthetic minimalist electronic objects but leave them traipsing their umbilicals behind them? Most of all, I hate having to lug cables around with me in my bag, and then inevitably have the wrong connector for the job at hand. When will there be a better way?
A few months ago, my partner and I refitted our rather tired kitchen. Pride of place has now been taken by our new induction cooktop. I had not previously appreciated how enlightening induction ovens are. Pots and pans heat extremely quickly, and yet the glass hob around and even under each pot is touchable and safe. Induction works by flowing oscillating electricity through coils of wire. This creates a fluctuating magnetic field, which in turn causes electric eddies to be induced in another metallic object, even when separated at some distance away. Heat is produced when the induced electricity flows through resistance in the metal.
Induction power was discovered by Michael Faraday in 1831 and further developed by Nikola Tesla in 1890s. An ethnic Serb from the Austrian Empire, Tesla emerged as an astonishing inventor and entrepreneur. He emigrated to the US in 1884 initially to work for Edison but thereafter founded a series of start-ups. His first company, Tesla Electric Light & Manufacturing, failed when his investors abandoned him to focus on a new utility company. As a failed entrepreneur, he had to resort to digging ditches as a labourer for a time.
His second company, Tesla Electric Company, invented the induction electric motor which uses a rotating metal drum inside an air filled sleeve. It was a major advance over the existing technology which used noisy, spark-generating commutators based on mechanical brushes, and which inevitably wear out over time. His patents for induction motors were then licensed to Westinghouse with a royalty for each machine.
Inventions
With his royalty fee income, Tesla became financially secure and went on to patent a number of other inventions. He bewildered the public with the first radio controlled model, a toy boat in Madison Square Gardens. Some thought it was being controlled by telepathy. He became particularly well known for his Tesla coil, which transmits electrical power by inductive coupling. Tesla gave a number of public performances of his inventions, astonishing public and experts alike in his ability to cause electric lamps to glow without physical connection.
For almost two decades until 1906, Tesla spent much of his fortune designing a system for the commercial transmission of electrical power without cables or wires. Based on his work on induction motors, coils and lighting, he believed it possible to transmit large amounts of power around the world without pylons or expensive underground cables. He established a prototype at Colorado Springs, with a Tesla coil in the megavolt range, producing highly visible electrical discharges. He struggled for further investment, but did persuade JP Morgan to become a lead investor for a larger prototype at Long Island, New York.
In 1899 Guglielmo Marconi made headlines in New York in demonstrating ship to shore radio communication. Tesla believed that Marconi’s radio system could only ever be used for direct line-of-sight communication. He tried to persuade Morgan that they should pivot Tesla’s electrical power distribution system into proving the viability of transatlantic communication. However Marconi then demonstrated long distance radio communication, using sites in Cornwall in the UK; St John’s, Newfoundland; and in Ireland, on Rosslare Strand and then Clifden. Morgan eventually seemed to lose faith in Tesla, and Tesla’s long distance power transmission and communication project ended in 1906.
Elon Musk’s Tesla automobile and energy company promotes Nikola Tesla’s name to us. Power transmission without cables, using induction, remains an area of commercial interest. A year ago, BMW announced an induction pad which can be laid on a garage floor, to wirelessly recharge its electric and hybrid models.
Among many urban examples worldwide, in the UK part of the Milton Keynes bus network is serviced by electric buses which pause for a few minutes over induction pads at the ends of the line to recharge their batteries. Some companies are experimenting with induction tracks in a road surface, which would enable recharging while a vehicle is moving. Global Energy Transmission, a Portland, Oregon, start-up has recently announced an induction fly zone which can be used to recharge inflight commercial drones.
A number of wireless recharging pads and mats, usually based on induction, are available for some smart devices. The Wireless Power Consortium, currently with about 250 member companies worldwide, is defining an industry standard specification called Qi. At the recent CES trade fair in Las Vegas, Powercast Corporation announced an FCC-approved wireless recharger using radio frequency energy which could operate up to 25m away from electric devices.
It is unlikely that Tesla’s dream of replacing transmission lines across cities and the countryside will ever be met anytime soon. However my own wish for umbilical free electronics appears to be coming closer.