WREL (technology)
Encyclopedia
For the Lexington, Virginia radio station, see WREL
.
WREL (Wireless Resonant Energy Link) is a form of wireless resonant energy transfer
technology developed by Intel.
The technology relies on strongly coupled electromagnetic resonators, a principle similar to the way a trained singer can shatter a glass using his/her voice. At the receiving resonator's natural frequency, energy is absorbed efficiently, just as a glass absorbs acoustic energy at its natural frequency. At the wall socket, power is put into magnetic field
s at a transmitting resonator - basically an antenna
. The receiving resonator is tuned to efficiently absorb energy from the magnetic field
, whereas nearby objects do not.
, for example, batteries
could be recharge
d when the laptop
gets within several feet of the transmit resonator.
was pioneered by Nikola Tesla
. Some of his later Tesla coils use a loosely coupled resonant magnetic power system. The lower coil was energised, and this transferred power via magnetic resonance to the resonant top coil where the high voltage was generated. This was predominantly done to avoid arcing and permit higher voltages.
For power supply for more everyday uses the technology is based on principles of WiTricity
proposed by Marin Soljacic
, a physicist at MIT.
Intel chief technology officer Justin Rattner
demonstrated powering a light bulb without the use of a plug
or wire
of any kind as he spoke at the California firm's annual developers forum in San Francisco 2008-08-21. Electricity
was sent wirelessly to a lamp on stage, lighting a 60 watt light bulb that uses more power than a typical laptop
computer.
; 2 Pi
times the ratio of the energy in the resonant circuit divided by its loss per cycle.
When two non resonating coils are placed some distance apart, some fraction of the magnetic field from one coil couples into the second, and so changes in the magnetic field of one coil generates a voltage at the other (in accordance with Faraday's law of induction
), however little of the energy will couple because most of the field will miss the receiver. The fraction of the field that does couple is called the coupling coefficient.
However, it may be seen that if some energy is placed in a 'sender' coil when it is in resonance then the coil will ring for a number of cycles before losing the energy to its resistance. Provided the Q of the transmitting circuit is high enough to overcome the coupling coefficient, then most of the power can eventually be absorbed by the receiving coil over several cycles and can be tapped off. The remaining power will be lost in the resistance of the sender, and some in the receiver coil also.
WREL
For WREL wireless energy transfer technology, see WREL .WREL is a News/Talk/Sports formatted broadcast radio station licensed to Lexington, Virginia, serving Lexington/Buena Vista area. WREL is owned and operated by First Media Radio, LLC....
.
WREL (Wireless Resonant Energy Link) is a form of wireless resonant energy transfer
Resonant energy transfer
Resonant energy transfer may refer to:*Förster resonance energy transfer*Resonant inductive coupling...
technology developed by Intel.
The technology relies on strongly coupled electromagnetic resonators, a principle similar to the way a trained singer can shatter a glass using his/her voice. At the receiving resonator's natural frequency, energy is absorbed efficiently, just as a glass absorbs acoustic energy at its natural frequency. At the wall socket, power is put into magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
s at a transmitting resonator - basically an antenna
Antenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
. The receiving resonator is tuned to efficiently absorb energy from the magnetic field
Magnetic field
A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude ; as such it is a vector field.Technically, a magnetic field is a pseudo vector;...
, whereas nearby objects do not.
Benefits
With this technology enabled in a laptopLaptop
A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
, for example, batteries
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
could be recharge
Recharge
Groundwater recharge or deep drainage or deep percolation is a hydrologic process where water moves downward from surface water to groundwater. This process usually occurs in the vadose zone below plant roots and is often expressed as a flux to the water table surface...
d when the laptop
Laptop
A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
gets within several feet of the transmit resonator.
History
Resonant magnetic power transferResonant energy transfer
Resonant energy transfer may refer to:*Förster resonance energy transfer*Resonant inductive coupling...
was pioneered by Nikola Tesla
Nikola Tesla
Nikola Tesla was a Serbian-American inventor, mechanical engineer, and electrical engineer...
. Some of his later Tesla coils use a loosely coupled resonant magnetic power system. The lower coil was energised, and this transferred power via magnetic resonance to the resonant top coil where the high voltage was generated. This was predominantly done to avoid arcing and permit higher voltages.
For power supply for more everyday uses the technology is based on principles of WiTricity
WiTricity
WiTricity, a portmanteau for "wireless electricity", is a trademark of WiTricity corporation referring to their devices and processes which use a form of wireless energy transfer including resonant energy transfer etc., the ability to provide electrical energy to remote objects without wires using...
proposed by Marin Soljacic
Marin Soljacic
Marin Soljačić is a Croatian physicist and electrical engineer known for wireless non-radiative energy transfer.-Biography:...
, a physicist at MIT.
Intel chief technology officer Justin Rattner
Justin Rattner
Justin Rattner is an Intel Senior Fellow, Corporate Vice President and director of Intel Labs. He also serves as the corporation's chief technology officer...
demonstrated powering a light bulb without the use of a plug
Plug
Plug may refer to:* Plug for the plughole in the bathtub, washbasin and sink* Plug , a short lived British comic that ran from 1977 until 1979, when it merged with The Beezer, which featured a character from The Bash Street Kids called Plug as it's main star.* Plug , a family of fishing lures*...
or wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
of any kind as he spoke at the California firm's annual developers forum in San Francisco 2008-08-21. Electricity
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
was sent wirelessly to a lamp on stage, lighting a 60 watt light bulb that uses more power than a typical laptop
Laptop
A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
computer.
Principles
In a resonating system, the quality of the resonance is determined by its Q factorQ factor
In physics and engineering the quality factor or Q factor is a dimensionless parameter that describes how under-damped an oscillator or resonator is, or equivalently, characterizes a resonator's bandwidth relative to its center frequency....
; 2 Pi
Pi
' is a mathematical constant that is the ratio of any circle's circumference to its diameter. is approximately equal to 3.14. Many formulae in mathematics, science, and engineering involve , which makes it one of the most important mathematical constants...
times the ratio of the energy in the resonant circuit divided by its loss per cycle.
When two non resonating coils are placed some distance apart, some fraction of the magnetic field from one coil couples into the second, and so changes in the magnetic field of one coil generates a voltage at the other (in accordance with Faraday's law of induction
Faraday's law of induction
Faraday's law of induction dates from the 1830s, and is a basic law of electromagnetism relating to the operating principles of transformers, inductors, and many types of electrical motors and generators...
), however little of the energy will couple because most of the field will miss the receiver. The fraction of the field that does couple is called the coupling coefficient.
However, it may be seen that if some energy is placed in a 'sender' coil when it is in resonance then the coil will ring for a number of cycles before losing the energy to its resistance. Provided the Q of the transmitting circuit is high enough to overcome the coupling coefficient, then most of the power can eventually be absorbed by the receiving coil over several cycles and can be tapped off. The remaining power will be lost in the resistance of the sender, and some in the receiver coil also.
See also
- WiTricityWiTricityWiTricity, a portmanteau for "wireless electricity", is a trademark of WiTricity corporation referring to their devices and processes which use a form of wireless energy transfer including resonant energy transfer etc., the ability to provide electrical energy to remote objects without wires using...
- Nikola TeslaNikola TeslaNikola Tesla was a Serbian-American inventor, mechanical engineer, and electrical engineer...
- Wireless energy transferWireless energy transferWireless energy transfer or wireless power is the transmission of electrical energy from a power source to an electrical load without artificial interconnecting conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible...
- Evanescent wave coupling
- Coupled inductors
- List of emerging technologies