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Inductive Charging
Inductive charging (also known as wireless charging or cordless charging) is a type of wireless power transfer. It uses electromagnetic induction to provide electricity to portable devices. Inductive charging is also used in vehicles, power tools, electric toothbrushes, and medical devices. The portable equipment can be placed near a charging station or inductive pad without needing to be precisely aligned or make electrical contact with a dock or plug. Inductive charging is named so because it transfers energy through inductive coupling. First, alternating current passes through an induction coil in the charging station or pad. The moving electric charge creates a magnetic field, which fluctuates in strength because the electric current's amplitude is fluctuating. This changing magnetic field creates an alternating electric current in the portable device's induction coil, which in turn passes through a rectifier to convert it to direct current. Finally, the direct current ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element; it has symbol Cu (from Latin ) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable, unalloyed metallic form. This means that copper is a native metal. This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Short Wave
Shortwave radio is radio transmission using radio frequencies in the shortwave bands (SW). There is no official definition of the band range, but it always includes all of the high frequency band (HF), which extends from 3 to 30 MHz (approximately 100 to 10 metres in wavelength). It lies between the medium frequency band (MF) and the bottom of the VHF band. Radio waves in the shortwave band can be reflected or refracted from a layer of electrically charged atoms in the atmosphere called the ionosphere. Therefore, short waves directed at an angle into the sky can be reflected back to Earth at great distances, beyond the horizon. This is called skywave or "skip" propagation. Thus shortwave radio can be used for communication over very long distances, in contrast to radio waves of higher frequency, which travel in straight lines (line-of-sight propagation) and are generally limited by the visual horizon, about 64 km (40 miles). Shortwave broadcasts of radio pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long Wave
In radio, longwave (also spelled long wave or long-wave and commonly abbreviated LW) is the part of the radio spectrum with wavelengths longer than what was originally called the medium-wave (MW) broadcasting band. The term is historic, dating from the early 20th century, when the radio spectrum was considered to consist of LW, MW, and short wave radio, short-wave (SW) radio bands. Most modern radio systems and devices use wavelengths which would then have been considered 'ultra-short' (i.e. very high frequency, VHF, ultra high frequency, UHF, and microwave). In contemporary usage, the term ''longwave'' is not defined precisely, and its intended meaning varies. It may be used for radio wavelengths longer than 1,000 m i.e. Frequency, frequencies smaller than 300 kilohertz (kHz), including the International Telecommunication Union (ITU) low frequency (LF, 30–300 kHz) and very low frequency (VLF, 3–30 kHz) bands. Sometimes the upper limit is taken to be hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Vehicle
An electric vehicle (EV) is a motor vehicle whose propulsion is powered fully or mostly by electricity. EVs encompass a wide range of transportation modes, including road vehicle, road and rail vehicles, electric boats and Submersible, submersibles, electric aircraft and electrically powered spacecraft propulsion, electric spacecraft. Early electric vehicles first came into existence in the late 19th century, when the Second Industrial Revolution brought forth electrification and mass utilization of DC motor, DC and AC motor, AC electric motors. Using electricity was among the preferred methods for motor vehicle propulsion as it provided a level of quietness, comfort and ease of operation that could not be achieved by the gasoline engine cars of the time, but range anxiety due to the limited energy storage offered by history of the battery, contemporary battery technologies hindered any mass adoption of private electric vehicles throughout the 20th century. Internal combustion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertz
The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base units is 1/s or s−1, meaning that one hertz is one per second or the Inverse second, reciprocal of one second. It is used only in the case of periodic events. It is named after Heinrich Hertz, Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. For high frequencies, the unit is commonly expressed in metric prefix, multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz). Some of the unit's most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utility Frequency
The utility frequency, (power) line frequency (American English) or mains frequency (British English) is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains electricity by country. During the development of commercial electric power systems in the late-19th and early-20th centuries, many different frequencies (and voltages) had been used. Large investment in equipment at one frequency made standardization a slow process. However, as of the turn of the 21st century, places that now use the 50 Hz frequency tend to use 220–240 V, and those that now use 60 Hz tend to use 100–127 V. Both frequencies coexist today (Japan uses both) with no great technical reason to prefer one ove ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Phones
A mobile phone or cell phone is a portable telephone that allows users to make and receive Telephone call, calls over a radio frequency link while moving within a designated telephone service area, unlike fixed-location phones (landline phones). This radio frequency link connects to the switching systems of a mobile phone operator, providing access to the public switched telephone network (PSTN). Modern mobile telephony relies on a cellular network architecture, which is why mobile phones are often referred to as 'cell phones' in North America. Beyond traditional Voice call, voice communication, digital mobile phones have evolved to support a wide range of additional services. These include text messaging, Multimedia Messaging Service, multimedia messaging, email, and internet access (via LTE (telecommunication), LTE, 5G NR or Wi-Fi), as well as short-range wireless technologies like Bluetooth, Infrared Data Association, infrared, and ultra-wideband (UWB). Mobile phones also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qi (standard)
Qi ( ) is an open standard for inductive charging developed by the Wireless Power Consortium. It allows compatible devices, such as smartphones, to receive power when placed on a Qi charger, which can be effective over distances up to 4 cm (1.6 in). Devices that implement the optional Magnetic Power Profile for magnetic attachment and alignment may be labelled Qi2 ( ). Qi version 1.0 was released in 2010; by 2017, it had been incorporated into more than 200 models of smartphones, tablets, and other devices. In December 2023, 351 manufacturers were working with the standard, including Apple, Asus, Google, Huawei, LG Electronics, Samsung, Xiaomi, and Sony. , the current version of the Qi specification is 2.1., which incorporates Apple's MagSafe technology to enhance wireless charging through magnetic alignment. The current standard supports charging speeds of up to 15 watts and aims to improve compatibility across devices from various manufacturers. Naming The name Qi () means ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonant Inductive Coupling
Resonant inductive coupling or magnetic phase synchronous coupling is a phenomenon with inductive coupling in which the coupling becomes stronger when the "secondary" (load-bearing) side of the loosely coupled coil resonates. A Transformer types#Resonant transformer, 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. Applications Various resonant coupling systems in use or are under development for short range (up to 2 meters) wireless electricity systems to power laptops, tablets, smartphones, robot vacuums, implanted medical devices, and vehicles like electric cars, SCMaglev trains and automated guided vehicles.10 kW) of resonant inductive energy transfer. High power levels are required for rapid recharging and high energy transfer efficiency is required both for operational economy and to avoid negative environment ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Auckland
The University of Auckland (; Māori: ''Waipapa Taumata Rau'') is a public research university based in Auckland, New Zealand. The institution was established in 1883 as a constituent college of the University of New Zealand. Initially located in a repurposed courthouse, the university has grown substantially over the years. As of 2024, it stands as the largest university in New Zealand by enrolment, teaching approximately 43,000 students across three major campuses in central Auckland. The university conducts teaching and learning within six faculties, two research institutes, and other institutes and centres. The City Campus, in the Auckland central business district, hosts the majority of students and faculties. History Origins The University of Auckland began as a constituent college of the University of New Zealand, founded on 23 May 1883 as ''Auckland University College''. Stewardship of the university during its establishment period was the responsibility of Joh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
