Thursday, December 13, 2012

The Future of Wireless Power

We are all familiar with distant telecoms and remote control over the internet (chatting, messaging, AV telecons, remote
control consoles) by using traditional telephone line modems or Internet Digital lines (ADSL, fiber) nowadays,
This is how data and information are transferred electronically (wired or wirelessly),
What about transferring energy and power ?!
Via power cables; Yes the technology exists and evolves; But feeding with power wirelessly; Is it possible and feasible?!
Luckily this technology evolved after long R&D's and become true and feasible:

Wireless power transfer

Forgotten knowledge: Tesla invented wireless power

Wireless power is a most wanted technology. It has already been invented by Nikola Tesla in 1888. The speaker read the papers, reproduced the theoretical and practical results. The theoretical idea to get highly efficient wireless power transmission is to separate the electric from the magnetic field, because magnetic field lines are closed curves near the device, while the electric field lines reach to infinity and receiver only needs common ground (the earth). This is done by special requirements to the sender and receiver antennas (form of the coil). The antenna form has been modeled in the software nec2 (variant xnec2c on debian). A lowcost PET bottle serves as the hull of the coil. Around 200 windings of insulated copper wire are manually applied to the bottle. A transmission in the range of 10 meters was reached, the power used is 100mW, from signal generator amplitude 10V and 1 MHz frequency. This will be shown.

Tesla Long Distance High-Power and High-Efficiency Wireless Energy Transmission is still a mystery to our technology. To better understand his claims that power can be transmitted to any distance on Earth with insignificant losses, and to see what challenges does this pose to the current technology, two simple prototypes of Tesla Magnifier have been built.

Understanding of the working principle was needed to build the prototypes with modern materials. All data was readily available on Internet: original Tesla's patents and articles from 1891-1919 related to wireless energy tramission. Information have led to optimal calculation of geometry for a Tesla Magnifier, a kind of resonant antenna used to transmit and/or receiver power.

In replicated prototype the oscillatory mode has been determined by measuring phase and magnitude of current and voltage at magnifier's feed line.

Some unexpected electrical conditions have been observed which were accurately reproduced using computer models in SPICE (electronic circuit simulation) and NEC2 (antenna simulation and electomagnetic field visualization).

Simulation has revealed geometry of the field around the Tesla Magnifier and it differs from the field around ordinary radio antenna (which radiates transversal electromagnetic wave) and could be a clue for faster-than-light energy transfer on planetary scale which Tesla claimed in his patents and articles.

Wireless power has been a promise for a few years now (if you know the pioneering work of Nikola Tesla, it's been a promise for about a century), but how close are we to really being able to cut the cord? And what difference does it make if you don't ever have to think about plugging in? Lastly, why are there so many different systems?

You can buy wireless power adapters for handsets and other devices, and wireless charging mats to put them down on, but they're not all the same.

When electricity travels through a power cord it's moving along the conductive copper (and into a battery through direct contact). Inductive charging creates an alternating electromagnetic field with a coil of wire – like the charging base of an electric 
toothbrush, an induction hob or a wireless power charging mat – and a second induction coil that takes power from the field and converts it back into current.

Wireless power systems like Palm's Touchstone charger, 
Powermat, GETPOWERPAD,Qualcomm's WiPower and Fulton's eCoupled (adopted by the Wireless Power Consortium under the name Qi and used in the Duracell charging mat) use higher frequencies and far thinner coils to achieve much higher efficiency. eCoupled and Powermat use tightly coupled near-field energy transfer; when using smaller coils, the device you're charging has to be close to the charging point and on a specific spot. This isn't just for low power; Qi goes up to 5W but eCoupled can charge something much larger than a phone and the Wireless Power Consortium is working on a standard for up to 120W.

One of our favorite wireless charging mats, the uPad, uses tightly-coupled inductive charging to recharge a wireless mouse (doing away with the usual wired docking station you perch the mouse on); turn it over and the other side of the mat is a small display that can show weather reports or news headlines – an accelerometer detects which way up you put it and powers that side. Sadly you can't buy the uPad; it was produced by MSR Asia as an anniversary gift to celebrate the lab's 10th anniversary in 2009 and 
Microsoft filed a patent in case it ever decides to produce them commercially.

Wireless Power IC Transmitter and Receiver Qi Compliant

Single-chip Wireless Power Transmitter and Receiver for Battery Charger

The IDTP9030 is the world's first true single-chip wireless power transmitter IC and the IDTP9020 is the industry's first multi-mode capable single-chip wireless power receiver IC. The highly integrated IDTP9030 is Qi certified, multi-mode capable, and reduces board footprint by 80 percent and bill-of-materials (BOM) cost by 50 percent compared to existing solutions. Both devices are capable of "multilingual" (multi-mode) operation, supporting both the Qi standard as well as proprietary formats for added features, improved safety, and increased power output capability.


Power wireless sensor networks by harvesting energy


Wireless-sensor networks and related technologies are important topics to engineers who work in system design. Although engineers who design systems for process or manufacturing control are familiar with distributed data acquisition and control, the architecture of systems with distributed intelligence is another relevant topic. Wireless data communication is yet another key topic, but so are self-organizing system design, network topologies, RF design, ruggedized system design, micropower design, energy harvesting, wireless delivery of power, energy storage, and data security in wireless systems. Moreover, although wireless-sensor networks have been around in significant numbers for perhaps a decade, their structure continues to evolve, causing almost daily growth in the number and diversity of technologies with which their designers must become adept.

Although these networks' architects can choose among a plethora of wireless-networking-protocol standards, in which low power consumption is a key requirement, they appear to favor ZigBee, an extension of the IEEE 802.15.4 standard. Compared with alternative protocols, such as Wi-Fi, ZigBee, with a fastest data rate of only 250kbps, is no speed demon. However, the speed seems to suffice for many industrial applications in which a priority is low power.

Wireless-sensor networks have long relied on batteries to power sensors deployed throughout large process and manufacturing facilities. At first, designers regarded the deployment of wireless sensors in relatively inaccessible locations in these facilities as a great boon. Such arrangements eliminated the need to route signal wiring through difficult-to-reach areas and often presented hazards to not only the installers but also the signal cables.

It then became obvious that the necessary labor for replacing sensor batteries could become a major ongoing cost in keeping these networks on the air. If a network incorporates, for example, 365 sensors—one for each day of the year, each with a signal conditioner that uses one battery—and the average battery life is one year, the plant manager must budget for the time to replace the battery in one sensor per day, every day of the year, including weekends and holidays. Also, it is nearly impossible to budget for the events that can occur when a system element fails unexpectedly, perhaps because a battery required replacement earlier than scheduled or a wire broke after it flexed one time too many.

Such concerns gave rise to the idea of energy harvesting—powering wireless sensors by converting, storing, and using small amounts of energy from such ambient sources as light, heat, and vibration. This promising new technology has drawn great interest, especially among academics, and is now starting to produce commercially worthwhile results.

The real objective
Somewhere in this scenario, some system designers, who perhaps had become fascinated with the "green" revolution, may have lost sight of the real objective. It's nice to minimize the amount of energy supplied to the network to power it, but, in most networks, that power is already low. A more important objective is often to minimize maintenance and its associated costs. A good way to reduce maintenance is to eliminate both remote power wiring—with its susceptibility to damage in rugged environments—and batteries—with their limited cycle life (the number of charge/discharge cycles they can typically withstand before their energy-storage capacity significantly diminishes). If the objective is reducing maintenance, further reducing network power consumption can begin to appear like an unattainable goal, whereas the idea of continually supplying energy to the sensors—wirelessly through RF fields—may start to sound surprisingly intriguing.



House Wirless Electricity



The reality of wireless electricity is close at hand, thanks to the efforts of engineers at MIT and the development and coming product offering of WiTricity, a Watertown-based company who is working on an appliance that will effectively eliminate wired appliances and devices in your living room.

The gist of the technology behind the company (as far as I understood it) has to do with matching the resonant frequencies of the magnetic fields of two devices to form one continuous magnetic field. This coupling of the magnetic fields allows for the transfer of energy via magnetism – and thus without wires. This method also avoids some of the dangers of transferring energy through magnetism. Pretty cool stuff.witricity_demo

Developed at MIT by a team of physicists, led by Professor Marin Solja?i?, the idea for wireless electric power was spawned in the brain of Professor Solja?i? when he became frustrated with plugging in his cell phone all of the time, not to mention remembering his cell phone charger when going places (I feel his pain here). Once the technology was developed, WiTricity, Inc, was spun out of the lab to develop commercial products that could be offered to the public.

The company is currently working on a device that is around the size of a small picture frame and can be installed behind the sheetrock on your walls or under counters in your kitchen. These devices will send the electro-magnetic waves out that will charge the devices setup around them. No information on the pricing of these devices, but you can bet that they'll be very popular when they hit the market. This idea is so compelling that the company could find itself going public very soon after it's product offering hits the market. The company has raised $4 million in venture funding to this point, and their initial product offering is apparently around 17 months away (look for it around New Year's 2011). Until then, check out this video:


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