A Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high-voltage, low-current, high frequency alternating-current electricity. Tesla experimented with a number of different configurations consisting of two, or sometimes three, coupled resonant electric circuits.
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force is equal or close to a natural frequency of the system on which it acts. When an oscillating force is applied at a resonant frequency of a dynamic system, the system will oscillate at a higher amplitude than when the same force is applied at other, non-resonant frequencies.
A resonator is a device or system that exhibits resonance or resonant behavior. That is, it naturally oscillates with greater amplitude at some frequencies, called resonant frequencies, than at other frequencies. The oscillations in a resonator can be either electromagnetic or mechanical. Resonators are used to either generate waves of specific frequencies or to select specific frequencies from a signal. Musical instruments use acoustic resonators that produce sound waves of specific tones. Another example is quartz crystals used in electronic devices such as radio transmitters and quartz watches to produce oscillations of very precise frequency.
Wireless power transfer (WPT), wireless power transmission, wireless energy transmission (WET), or electromagnetic power transfer is the transmission of electrical energy without wires as a physical link. In a wireless power transmission system, a transmitter device, driven by electric power from a power source, generates a time-varying electromagnetic field, which transmits power across space to a receiver device, which extracts power from the field and supplies it to an electrical load. The technology of wireless power transmission can eliminate the use of the wires and batteries, thus increasing the mobility, convenience, and safety of an electronic device for all users. Wireless power transfer is useful to power electrical devices where interconnecting wires are inconvenient, hazardous, or are not possible.
A plasma globe or plasma lamp is a clear glass container/ball filled with a mixture of various noble gases with a high-voltage electrode in the center of the container.
A spark-gap transmitter is an obsolete type of radio transmitter which generates radio waves by means of an electric spark. Spark-gap transmitters were the first type of radio transmitter, and were the main type used during the wireless telegraphy or "spark" era, the first three decades of radio, from 1887 to the end of World War I. German physicist Heinrich Hertz built the first experimental spark-gap transmitters in 1887, with which he proved the existence of radio waves and studied their properties.
An Oudin coil, also called an Oudin oscillator or Oudin resonator, is a resonant transformer circuit that generates very high voltage, high frequency alternating current (AC) electricity at low current levels, used in the obsolete medical field of electrotherapy around the turn of the 20th century. It is very similar to the earlier Tesla coil, patented in 1891, with the difference being that the Oudin coil was connected as an autotransformer. It was invented in 1893 by French physician Paul Marie Oudin as a modification of physician Jacques Arsene d'Arsonval's electrotherapy equipment and used in quack medicine until perhaps 1930. The high voltage output terminal of the coil was connected to an insulated handheld electrode which produced luminous brush discharges, which were applied to the patient's body to treat various medical conditions in electrotherapy.
The internal electrodeless lamp, induction lamp, or electrodeless induction lamp is a gas-discharge lamp in which an electric or magnetic field transfers the power required to generate light from outside the lamp envelope to the gas inside. This is in contrast to a typical gas discharge lamp that uses internal electrodes connected to the power supply by conductors that pass through the lamp envelope. Eliminating the internal electrodes provides two advantages:
A loop antenna is a radio antenna consisting of a loop or coil of wire, tubing receiving predominantly the magnetic component of the electromagnetic wave, or other electrical conductor usually fed by a balanced source or feeding a balanced load. Within this physical description there are two distinct antenna types:
Electrical resonance occurs in an electric circuit at a particular resonant frequency when the impedances or admittances of circuit elements cancel each other. In some circuits, this happens when the impedance between the input and output of the circuit is almost zero and the transfer function is close to one.
WiTricity is an American wireless charging technology company based in Watertown, Massachusetts. The Massachusetts Institute of Technology (MIT) spin-off was founded by professor Marin Soljačić in 2007. WiTricity technology allows wireless power transfer over distance via magnetic resonance and the company licenses technology and reference designs for wireless electrical vehicle (EV) charging as well as consumer products such as laptops, mobile phones and televisions.
Marin Soljačić is a Croatian-American physicist and electrical engineer known for wireless non-radiative energy transfer.
eCoupled is a proprietary near-field wireless energy transfer technology developed by Fulton Innovation, a division of Alticor. It provides wireless power transfer via inductive coupling between a primary transmission coil and a secondary receiving coil. A single primary coil can provide power to multiple secondary coils at the same time.
Resonant inductive coupling or magnetic phase synchronous coupling is a phenomenon with inductive coupling where the coupling becomes stronger when the "secondary" (load-bearing) side of the loosely coupled coil resonates. A resonant transformer of this type is often used in analog circuitry as a bandpass filter. Resonant inductive coupling is also used in wireless power systems for portable computers, phones, and vehicles.
The Wireless Power Consortium (WPC) is a multinational technology consortium formed in December 17, 2008 and based in Piscataway, New Jersey. Its mission is to create and promote wide market adoption of its interface standards Qi, Ki Cordless Kitchen, and Qi Medium Power for inductive charging. It is an open membership of Asian, European, and American companies, working toward the global standardization of wireless charging technology.
A MEMSmagnetic field sensor is a small-scale microelectromechanical systems (MEMS) device for detecting and measuring magnetic fields (Magnetometer). Many of these operate by detecting effects of the Lorentz force: a change in voltage or resonant frequency may be measured electronically, or a mechanical displacement may be measured optically. Compensation for temperature effects is necessary. Its use as a miniaturized compass may be one such simple example application.
Qi is an open interface standard that defines wireless power transfer using inductive charging over distances of up to 4 cm, developed by the Wireless Power Consortium. The system uses a charging pad and a compatible device, which is placed on top of the pad, charging via resonant inductive coupling.
A magnetoquasistatic field is a class of electromagnetic field in which a slowly oscillating magnetic field is dominant. A magnetoquasistatic field is typically generated by low-frequency induction from a magnetic dipole or a current loop. The magnetic near-field of such an emitter behaves differently from the more commonly used far-field electromagnetic radiation. At low frequencies the rate of change of the instantaneous field strength with each cycle is relatively slow, giving rise to the name "magneto-quasistatic". The near field or quasistatic region typically extends no more than a wavelength from the antenna, and within this region the electric and magnetic fields are approximately decoupled.
Nikola Tesla patented the Tesla coil circuit on April 25, 1891. and first publicly demonstrated it May 20, 1891 in his lecture "Experiments with Alternate Currents of Very High Frequency and Their Application to Methods of Artificial Illumination" before the American Institute of Electrical Engineers at Columbia College, New York. Although Tesla patented many similar circuits during this period, this was the first that contained all the elements of the Tesla coil: high voltage primary transformer, capacitor, spark gap, and air core "oscillation transformer".
SAE J2954 is a standard for wireless power transfer (WPT) for electric vehicles led by SAE International. It defines three classes of charging speed, WPT 1, 2 and 3, at a maximum of 3.7 kW, 7.7 kW and 11 kW, respectively. This makes it comparable to medium-speed wired charging standards like the common SAE J1772 system. A much more powerful WPT9 is being defined in J2954/2 for 500 kW charging for heavy-duty vehicles which have the room necessary to mount the larger induction plate.
