|
Leyden Jar
A Leyden jar (or Leiden jar, or archaically, sometimes Kleistian jar) is an electrical component that stores a high-voltage electric charge (from an external source) between electrical conductors on the inside and outside of a glass jar. It typically consists of a glass jar with metal foil cemented to the inside and the outside surfaces, and a metal terminal projecting vertically through the jar lid to make contact with the inner foil. It was the original form of capacitor (also called a ''condenser''). Its invention was a discovery made independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden), Netherlands in 1745–1746. The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electrostatics. It was the first means of accumulating and preserving electric charge in large quantities that could be discharged at the exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Component
An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements. Electronic components have a number of electrical terminals or leads. These leads connect to other electrical components, often over wire, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Basic electronic components may be packaged discretely, as arrays or networks of like components, or integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices. The following list of electronic components focuses on the discrete version of these components, treating such packages as components ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-Socratic Philosophy
Pre-Socratic philosophy, also known as early Greek philosophy, is ancient Greek philosophy before Socrates. Pre-Socratic philosophers were mostly interested in cosmology, the beginning and the substance of the universe, but the inquiries of these early philosophers spanned the workings of the natural world as well as human society, ethics, and religion. They sought explanations based on natural law rather than the Divinity, actions of gods. Their work and writing has been almost entirely lost. Knowledge of their views comes from ''testimonia'', i.e. later authors' discussions of the work of pre-Socratics. Philosophy found fertile ground in the ancient Greek world because of the close ties with neighboring civilizations and the rise of autonomous civil entities, ''polis, poleis''. Pre-Socratic philosophy began in the 6th century BCE with the three Milesian school, Milesians: Thales, Anaximander, and Anaximenes of Miletus, Anaximenes. They all attributed the ''arche'' (a word that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polish–Lithuanian Commonwealth
The Polish–Lithuanian Commonwealth, formally known as the Kingdom of Poland and the Grand Duchy of Lithuania, and, after 1791, as the Commonwealth of Poland, was a bi-confederal state, sometimes called a federation, of Crown of the Kingdom of Poland, Poland and Grand Duchy of Lithuania, Lithuania ruled by a common Monarchy, monarch in real union, who was both King of Poland and List of Lithuanian monarchs, Grand Duke of Lithuania. It was one of the largest and most populous countries of 16th- to 17th-century Europe. At its largest territorial extent, in the early 17th century, the Commonwealth covered almost and as of 1618 sustained a multi-ethnic population of almost 12 million. Polish language, Polish and Latin were the two co-official languages. The Commonwealth was established by the Union of Lublin in July 1569, but the Crown of the Kingdom of Poland and the Grand Duchy of Lithuania had been in a ''de facto'' personal union since 1386 with the marriage of the Polish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Matthias Bose
Georg Matthias Bose (22 September 1710 – 17 September 1761), also known as Mathias Bose, was a famous electrical experimenter in the early days of the development of electrostatic generator, electrostatics. He is credited with being the first to develop a way of temporarily storing static charges by using an Insulator (electricity), insulated Electrical conductor, conductor (called a prime conductor). His demonstrations and experiments raised the interests of the German scientific community and the public in the development of electrical research. Early life He was born the son of a merchant and educated at the Leipzig University, University of Leipzig, receiving his Master's degree in 1727. In 1738, he became the professor of natural philosophy at the University of Wittenberg. As part of his course in physics, he revived experimentation with a glass-globe machine following the design of Francis Hauksbee, Francis Hauksbee the Elder, and he later vastly improved on the machine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pomerania
Pomerania ( pl, Pomorze; german: Pommern; Kashubian: ''Pòmòrskô''; sv, Pommern) is a historical region on the southern shore of the Baltic Sea in Central Europe, split between Poland and Germany. The western part of Pomerania belongs to the German states of Mecklenburg-Western Pomerania and Brandenburg, while the eastern part belongs to the West Pomeranian, Pomeranian and Kuyavian-Pomeranian voivodeships of Poland. Its historical border in the west is the Mecklenburg-Western Pomeranian border '' Urstromtal'' which now constitutes the border between the Mecklenburgian and Pomeranian part of Mecklenburg-Western Pomerania, while it is bounded by the Vistula River in the east. The easternmost part of Pomerania is alternatively known as Pomerelia, consisting of four sub-regions: Kashubia inhabited by ethnic Kashubians, Kociewie, Tuchola Forest and Chełmno Land. Pomerania has a relatively low population density, with its largest cities being Gdańsk and Szczecin. Ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deacon
A deacon is a member of the diaconate, an office in Christian churches that is generally associated with service of some kind, but which varies among theological and denominational traditions. Major Christian churches, such as the Catholic Church, the Oriental Orthodox Churches, the Eastern Orthodox Church, the Scandinavian Lutheran Churches, the Methodist Churches, the Anglican Communion, and the Free Church of England, view the diaconate as an order of ministry. Origin and development The word ''deacon'' is derived from the Greek word (), which is a standard ancient Greek word meaning "servant", "waiting-man", "minister", or "messenger". It is generally assumed that the office of deacon originated in the selection of seven men by the apostles, among them Stephen, to assist with the charitable work of the early church as recorded in Acts of the Apostles chapter 6. The title ''deaconess'' ( grc, διακόνισσα, diakónissa, label=none) is not found in the Bible. Ho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrotherapy
Electrotherapy is the use of electrical energy as a medical treatment. In medicine, the term ''electrotherapy'' can apply to a variety of treatments, including the use of electrical devices such as deep brain stimulators for neurological disease. The term has also been applied specifically to the use of electric current to speed wound healing. Additionally, the term "electrotherapy" or "electromagnetic therapy" has also been applied to a range of alternative medical devices and treatments. Medical uses Electrotherapy is primarily used in physical therapy for: * relaxation of muscle spasms * prevention and retardation of disuse atrophy * increase of local blood circulation * muscle rehabilitation and re-education * electrical muscle stimulation * maintaining and increasing range of motion * management of chronic and intractable pain including diabetic neuropathy * acute post-traumatic and post-surgical pain * post-surgical stimulation of muscles to prevent venous thrombosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spark-gap Transmitter
A spark-gap transmitter is an obsolete type of radio transmitter which generates radio waves by means of an electric spark."Radio Transmitters, Early" in 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. A fundamental limitation of spark-gap transmitters is that they generate a series of brief transient pulses of radio waves called damped waves; they are unable to produce the continuous waves used to carry audio (sound) in modern AM or FM radio transmission. So spark-gap transmitters could not transmit audio, and instead transmitted information by radiotelegraphy; the operator switched the transmitter on and off with a telegraph key, creating pulses ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corona Discharge
A corona discharge is an electrical discharge caused by the ionization of a fluid such as air surrounding a conductor carrying a high voltage. It represents a local region where the air (or other fluid) has undergone electrical breakdown and become conductive, allowing charge to continuously leak off the conductor into the air. A corona discharge occurs at locations where the strength of the electric field (potential gradient) around a conductor exceeds the dielectric strength of the air. It is often seen as a bluish glow in the air adjacent to pointed metal conductors carrying high voltages, and emits light by the same mechanism as a gas discharge lamp. In many high voltage applications, corona is an unwanted side effect. Corona discharge from high voltage electric power transmission lines constitutes an economically significant waste of energy for utilities. In high voltage equipment like cathode ray tube televisions, radio transmitters, X-ray machines, and particl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrode
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air). Electrodes are essential parts of batteries that can consist of a variety of materials depending on the type of battery. The electrophore, invented by Johan Wilcke, was an early version of an electrode used to study static electricity. Anode and cathode in electrochemical cells Electrodes are an essential part of any battery. The first electrochemical battery made was devised by Alessandro Volta and was aptly named the Voltaic cell. This battery consisted of a stack of copper and zinc electrodes separated by brine-soaked paper disks. Due to fluctuation in the voltage provided by the voltaic cell it wasn't very practical. The first practical battery was invented in 1839 and named the Daniell cell after John Frederic Daniell. Still making use of the zinc–copper electrode combination. Since then many more batteries have be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volt
The volt (symbol: V) is the unit of electric potential, electric potential difference (voltage), and electromotive force in the International System of Units (SI). It is named after the Italian physicist Alessandro Volta (1745–1827). Definition One volt is defined as the electric potential between two points of a conducting wire when an electric current of one ampere dissipates one watt of power between those points. Equivalently, it is the potential difference between two points that will impart one joule of energy per coulomb of charge that passes through it. It can be expressed in terms of SI base units ( m, kg, second, s, and ampere, A) as : \text = \frac = \frac = \frac. It can also be expressed as amperes times ohms (current times resistance, Ohm's law), webers per second (magnetic flux per time), watts per ampere (power per current), or joules per coulomb (energy per charge), which is also equivalent to electronvolts per elementary charge: : \text = \tex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Voltage
High voltage electricity refers to electrical potential large enough to cause injury or damage. In certain industries, ''high voltage'' refers to voltage above a certain threshold. Equipment and conductors that carry high voltage warrant special safety requirements and procedures. High voltage is used in electrical power distribution, in cathode ray tubes, to generate X-rays and particle beams, to produce electrical arcs, for ignition, in photomultiplier tubes, and in high-power amplifier vacuum tubes, as well as other industrial, military and scientific applications. Definition The numerical definition of depends on context. Two factors considered in classifying a voltage as high voltage are the possibility of causing a spark in air, and the danger of electric shock by contact or proximity. The International Electrotechnical Commission and its national counterparts (IET, IEEE, VDE, etc.) define ''high voltage'' as above 1000 V for alternating current, and at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
