By Hamilton Carter and John Blyler
Legendary physicist and inventor, Nikola Tesla, conducted some of his most shrouded work in a forgotten lab at Wardenclyffe, NY. On November 5, 2011, that lab will come alive as the site of a major event (see Figure 1).
|Figure 1: QSL card image, created by ham radio cartoonist, Jeff Murray, K1NSS.|
At the turn of the 20th century, The Wardenclyffe lab was built to provide wireless power and communications across the planet. That potential was never realized as the world’s most powerful capitalist – J.P. Morgan – removed his funding from the project before it was completed.
On November 5th, ham operators will broadcast from the Wardenclyffe lab to raise awareness about a restoration effort led by the TeslaScienceCenter.org - a non-profit that will also host a Tesla conference at Brookhaven National Laboratory on the same day (see Figure 2).
|Figure 2: Physicist Nikola Tesla’s Wardenclyffe laboratory, then and now.|
Also on that day, a special ham radio event station, YU0TESLA, will broadcast from Telsa’s homeland in Belgrade, Serbia.
Finally, the New Yorker Hotel will serve as the final broadcast center for the event. Telsa spent his dying years working in the basement of this historic hotel.
Want to learn more about the history behind the Wardenclyffe lab and the reawakening of Telsa’s original vision for wireless power? Then read on.
Legendary Physicist and Inventor
Nikola Tesla, a scientist, engineer, and inventor that lived during the turn of the 20th century, has been the unheralded inventor of radio. Also, he created the alternating current system that supplies power to the United States as well as the rest of the world. Every time someone plugs in an electrical or electronic device, they are using one of Tesla’s inventions.
Tesla’s last big project started in Colorado Springs, CO, and ended in Shoreham, NY on Long Island. In addition to providing radio communications for the world, he was convinced that power could be provided wirelessly as well. He built a prototype of his system in Colorado Springs. It pulled so much power from the city’s generators that they caught on fire. Tesla had to pay to have them reconstructed to meet his specifications. This is the laboratory that was featured in the movie, ‘The Prestige’ (see Figure 3).
|Figure 3: David Bowie as Nikola Tesla in The Prestige (2006). (Courtesy of Touchstone Pictures 2011)|
After prototyping his wireless power system in Colorado Springs, Tesla returned to New York to obtain startup funding. Soon after, construction began on Wardenclyffe Laboratory in Shoreham, NY. The laboratory, architected by Stanford White, was supposed to the be the center of ‘Radio City’ where people would send telegrams, voice messages and pictures all over the world.
The planned system was a precursor of the Internet – almost 100 years earlier! As the 186 foot tall tower was constructed Tesla’s funding sources got wind of Tesla’s plan to supply power for free to the world. That news combined with Marconi’s successful trans-Atlantic radio transmission led to Tesla’s funding sources pulling all support. Wardeclyfe was operated once and then fell into disrepair (see Figure 4).
|Figure 4: Even in disrepair, Wardenclyffe lab still contains treasured engineering artifacts. (Courtesy of Hamilton Carter)|
Eventually the tower was torn down and sold for scrap, but the laboratory building remains on the site to this day. Now, the building is for sale. A group of citizens in Shoreham, NY, are trying to purchase the building to turn it into a science museum and study center – the Tesla Science Center. To get the word out, the citizens are hosting on November 5th, 2011, a Tesla conference in Rocky Point, NY, just a few miles from Wardenclyffe.
In conjunction with the conference, radio transmissions via amateur radio special event station W3T will be sent from Wardencllyffe for the first time in over 100 years. The station will operate in conjunction with several other stations from all over the world to commemorate the event. Getting the Wardenclyffe back on the air for one day is a story of global connections, Internet technology and serendipitous timing.
Wireless Power Reawakens
Physicist Nikola Tesla’s discoveries in wireless power has slumbered for the last century or so. Only in the last decade has interest in Tesla’s forgotten research been awakened, thanks in large measure to the proliferation of high performance, power-hungry mobile devices.
Among the many recent announcements of wireless power research and products, perhaps the one most closely aligned with Tesla’s original work was come from the telecommunication industry. Several years ago, cell-phone maker Nokia was developing technology to transfer enough power from ambient radio waves to maintain a healthy charge on a cell-phone handset. The ambient sources of electromagnetic (EM) radiation included transmissions from Wi-Fi, mobile phone, TV and other antennas.
To date, the power harvested from EM transmissions is low, in the neighborhood of 50 milliwatts. This is enough power to slowly recharge a phone that has already been powered down. Still, it is a start.
Today’s inventors take advantage of resonant coupling to harvest EM transmissions. As the name implies, magnetic coupling is achieve at resonance – i.e., the same frequency – between the EM source and the harvesting receiver.
During an Intel research project demonstration, the chip company used a large coil source with supporting electronics to create current oscillating at 7 MHz. The harvesting receiver coil was tuned to the same frequency as the source. The resulting resonant energy transfer achieved 80 percent efficiency within a range of about a meter.
|Figure 5: Intel researches resonant wireless power transmission. (Courtesy of Kate Greene)|
One way to increase the amount of transferred power while extending the range is to harvest the EM signal at many different frequencies. This requires a wideband receiver to capture signals between 500 MHz to 10 GHz, noted Nokia researchers.
Today, wireless power finally appears poised to enter mainstream consumer devices. Earlier this year, Texas Instruments (TI) announced a Qi-compliant wireless power receiver which was 80 percent smaller than its previous chip. Qi is a wireless charging standard developed by the Wireless Power Consortium (WPC).
The small size of TI’s subsystem should make it easier for manufacturers to incorporate wireless power recharging into many new devices; from cell-phones to game consoles, digital cameras and more. The company claims that the power chip will provide 93% peak efficiency while allowing charge rates comparable to AC adapter. No range limit information was available (see Figure 6).
|Figure 6: TI’s wireless power charging subsystem.|