23-12-2010, 02:40 PM
Prepared by:Ankit Mittal
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Witricity
Wireless- Wireless communication is the transfer of information over a distance without the use of enhanced electrical conductors or "wires". The distances involved may be short (a few meters as in television remote control) or long (thousands or millions of kilometers for radio communications).
SAN – Storage Area Network
Seminar Report by:-
Name - Aditi Malik
Roll No.- 072903100
Branch - Electronics and communication
Witricity - Wireless Electricity
Wireless Electricity-Wireless energy transfer or Wireless Power is the process that takes place in any system where electrical energy is transmitted from a power source to an electrical load without interconnecting wires. Wireless transmission is useful in cases where instantaneous or continuous energy transfer is needed but interconnecting wires are inconvenient, hazardous, or impossible
Wireless energy transfer is different from wireless transmission of information, such as radio, where the signal-to-noise ratio (SNR) or the percentage of power received becomes critical only if it is too low to adequately recover the signal. With wireless power transmission, efficiency is the more important parameter
The first mover and innovator
Nikola Tesla was the first to Experiment with
wireless electricity, but ultimately failed after
losing his key financial backing in the late 1800
There are certain small but very useful discoveries made in history, which changed the world forever, Newton’s gravitational law, Watt’s steam engine, Thomson’s bulb and many more. But a renaissance occurred with the invention of Electromagnetic Waves by Maxwell.
Tesla began working with Thomas Edison, but the two men were worlds apart in both their science and cultures (the fact that Tesla's alternating-current concept posed a direct threat to sales of Edison's direct-current devices probably didn't help) and they soon went their separate ways.
Tesla invented the alternating-current generator that provides your light and electricity, the transformer through which it is sent, and even the high voltage coil of your picture tube.
Early Visions Of wireless Power
Nikola Tesla’s Wardenclyffe tower built on Long Island, NY in 1904 . The tower was destroyed in 1917.
Nikola Tesla’s Wardenclyffe toer built on long Island , NY in 1904 was destroy in 1917.
As this tower are build up to transfer wireless electricity and suppose to transfer electric power any where on earth . They are suppose to place near the north pole of Earth . This stuff works that time but stop due to security purpose and due to financially problem.
We Human Love Electricity
Trillion Of Towers Around Us
Batteries
40 Billion Disposable Batteries / Yr.
What Happen To This Batteries After Use
Batteries Disintegrate and end up here.
The forgotten invention is reborn in 2007
The idea of wireless electricity has been around since the early days of the Tesla coil. But thanks to a group of MIT scientists, "WiTricity" (as these scientists call it) is now one step closer to practical reality.
How It Works
They Power up 60W Electric Bulb From a Power Source 7 feet away
The experimental design was constituted of two copper coils, each a self resonant system . One of the coil connected to an AC power called resonant source. The other coil called , the resonant capture device was connected to light bulb.
The power source and capture devise was suspended in mid-air with nyclon thread at a distance that range from few cm to 2.5 meter.
At the resonant source the standard 60 hz current convert to 10Mhz and feed into transmitting coil. The oscillating current in transmitting coil cause the coil to emit a 10 Mhz field. As the capture coil is of same dimension and it is in resonate with the source coil at same frequency called magnetic induction, pick up the energy from source coil magnetic field.
So this magnetic field induce current in the capture coil, light the bulb.
They got 50 % efficiency , buy the way that’s still a couple of time more efficient then a battery could be to do same thing .
Witricity Technology : The Basics
Electricity: The flow of electrons (current) through a conductor (like a wire), or charges through the atmosphere (like lightning). A convenient way for energy to get from one place to another!
WiTricity technology is—transferring electric energy or power over distance without wires .With the basics of Electricity and Magnetisum
Magnetism:
A fundamental force of nature, which causes certain types of materials to attract or repel each other . Permanent magnets, like the ones on your refrigerator and the earth’s magnetic field, are examples of objects having constant magnetic fields.
Oscillating magnetic fields vary with time, and can be generated by alternating current (AC) flowing on a wire. The strength, direction, and extent of magnetic fields are often represented and visualized by drawings of the magnetic field lines.
Electromagnetism:
A term for the interdependence of time-varying electric and magnetic fields. For example, it turns out that an oscillating magnetic field produces an electric field and an oscillating electric field produces a magnetic field.
Magnetic Induction:
A loop or coil of conductive material like copper, carrying an alternating current (AC), is a very efficient structure for generating or capturing a magnetic field.
Energy/Power Coupling:
Energy coupling occurs when an energy source has a means of transferring energy to another object. One simple example is a locomotive pulling a train car—the mechanical coupling between the two enables the locomotive to pull the train, and overcome the forces of friction and inertia that keep the train still—and, the train moves. Magnetic coupling occurs when the magnetic field of one object
Resonance:
Resonance is a property that exists in many different physical systems. It can be thought of as the natural frequency at which energy can most efficiently be added to an oscillating system
WiTricity Technology:
WiTricity power sources and capture devices are specially designed magnetic resonators that efficiently transfer power over large distances via the magnetic near-field. These proprietary source and device designs and the electronic systems that control them support efficient energy transfer over distances that are many times the size of the sources/devices themselves.
How It Works
Imagine a coil there is a capacitor to it too.
And if u can cause that coil to resonate, what will happen , it pulse at alternating frequency , at fierily high frequency.
And if u can bring another coil , close enough to source that will only work exactly at resonate frequency , you can actually get them to what is called strongly couple and transfer energy between them
Theoretically one stationary coil in a room could power multiple devices with receiving coils .
No more messy wires, and with widespread enough use it could even eliminate costly batteries.
What About Safety?
Non-radiative power transfer – Uses magnetic near field
Magenetic fields are safe for people and animals
Heighly resonant coupling minimizes energy transfer to “ off- resonant” objects
Witricity systems are designed to meet in its all safety guidelines
WiTricity Applications
Direct Wireless Power—when all the power a device needs is provided wirelessly, and no batteries are required. This mode is for a device that is always used within range of its WiTricity power source
Automatic Wireless Charging—when a device with rechargeable batteries charges itself while still in use or at rest, without requiring a power cord or battery replacement. This mode is for a mobile device that may be used both in and out of range of its WiTricity power source.
Features and Benefits
Highly Resonant Strong Coupling-High Efficiency Over Distance
Energy Transfer via Magnetic Near Field-Penetrates and Wraps-Around Obstacles
Non- Radiative Energy Transfer -Safe for People and Animals
Scalable Design-From Milli watts to Kilowatts
Flexible Geometry-Devices That Can Fit Into OEM Products
WiTricity’s technology is more than… Traditional Magnetic Induction
WiTricity’s technology is different than… Radiative Power Transfer
WiTricity’s technology is different than… Magnetic Resonance Imaging(MRI)
Highly Resonant Strong Coupling Provides High Efficiency Over Distance -WiTricity's mode of wireless power transfer is highly efficient over distances ranging from centimeters to several meters. We define efficiency as the amount of usable electrical energy that is available to the device being powered, divided by the amount of energy that is drawn by the WiTricity source. In many applications, efficiency can exceed 90%. And WiTricity sources only transfer energy when it is needed. When a WiTricity powered device no longer needs to capture additional energy, the WiTricity power source will automatically reduce its power consumption to a power saving “idle” state
Energy Transfer via Magnetic Near Field Can Penetrate and Wrap Around Obstacles -The magnetic near field has several properties that make it an excellent means of transferring energy in a typical consumer, commercial, or industrial environment. Most common building and furnishing materials, such as wood, gypsum wall board, plastics, textiles, glass, brick, and concrete are essentially “transparent” to magnetic fields—enabling WiTricity technology to efficiently transfer power through them. In addition, the magnetic near field has the ability to “wrap around” many metallic obstacles that might otherwise block the magnetic fields.
Non-Radiative Energy Transfer is Safe for People and Animals -WiTricity’s technology is a non-radiative mode of energy transfer, relying instead on the magnetic near field. Magnetic fields interact very weakly with biological organisms—people and animals—and are scientifically regarded to be safe. Professor Sir John Pendry of Imperial College London, a world renowned physicist, explains: “The body really responds strongly to electric fields, which is why you can cook a chicken in a microwave. But it doesn't respond to magnetic fields. As far as we know the body has almost zero response to magnetic fields in terms of the amount of power it absorbs." Evidence of the safety of magnetic fields is illustrated by the widespread acceptance and safety of household magnetic induction cooktops.
Through proprietary design of the WiTricity source, electric fields are almost completely contained within the source. This design results in levels of electric and magnetic fields which fall well within regulatory guidelines. Thus WiTricity technology doesn’t give rise to radio frequency emissions that interfere with other electronic devices, and is not a source of electric and magnetic field levels that pose a risk to people or animals.
Scalable Design Enables Solutions from milliwatts to Kilowatts -WiTricity systems can be designed to handle a broad range of power levels. The benefits of highly efficient energy transfer over distance can be achieved at power levels ranging from milliwatts to several kilowatts
WiTricity’s technology is more than… -Traditional Magnetic Induction -The power exchange efficiency of some induction systems is improved by utilizing resonant circuits. These so-called resonantly enhanced induction techniques are used in certain medical implants and high-frequency RFIDs for example.
WiTricity’s technology is different than… Radiative Power Transfer -WiTricity’s technology for power transfer is non-radiative and relies on near-field magnetic coupling. Many other techniques for wireless power transfer rely on radiative techniques, either broadcasted or narrow beam (directed radiation) transmission of radio, or light waves.
WiTricity’s technology is different than… Magnetic Resonance Imaging(MRI) -Many people assume that WiTricity’s “Resonant Magnetic Coupling” must be similar to magnetic resonance imaging (MRI) technology, however, the technologies are similar in name only. MRI is, as its name suggests, a technology for using magnetism as a basis for diagnostic imaging of soft tissue in the human body. It utilizes a strong DC magnet to orient the magnetic fields of atoms within tissues, and radio frequency fields to manipulate those atoms in a selective way, so that tissues and structures can be imaged clearly. The “resonance” referred to in “MRI” refers to the resonance of atomic structures. MRI is not considered to be a method for wireless power transfer.
PROs
Less accidents and instances of electrocution
Convenient to users who use products that can be charged through WiTricity
Could eliminate the need for an inefficient, costly, and capital intensive grid of cables, towers and substations
Gateway to other break through technological advances
Eliminate mess of cords and power strips used to charge products
Your home would keep your gadgets constantly powered up
Could eliminate batteries
Magnetic fields have little affect on biological organisms – but still needs more testing
