Who developed the capacitor?
Supercapacitor
Since capacitors' energy content increases with the square of the voltage, researchers were looking for a way to increase the electrolyte's breakdown voltage. In 1994 using the anode of a 200V high voltage tantalum electrolytic capacitor, David A. Evans developed an "Electrolytic-Hybrid Electrochemical Capacitor". These capacitors combine features of electrolytic and electrochemical capacitors. They combine the high dielectric strength of an anode from an electrolytic capacitor with the high capacitance of a pseudocapacitive metal oxide (ruthenium (IV) oxide) cathode from an electrochemical capacitor, yielding a hybrid electrochemical capacitor. Evans' capacitors, coined Capattery, had an energy content about a factor of 5 higher than a comparable tantalum electrolytic capacitor of the same size. Their high costs limited them to specific military applications.
Dynamic random-access memory
In 1964, Arnold Farber and Eugene Schlig, working for IBM, created a hard-wired memory cell, using a transistor gate and tunnel diode latch. They replaced the latch with two transistors and two resistors, a configuration that became known as the Farber-Schlig cell. In 1965, Benjamin Agusta and his team at IBM created a 16-bit silicon memory chip based on the Farber-Schlig cell, with 80 transistors, 64 resistors, and 4 diodes. In 1966, DRAM was invented by Dr. Robert Dennard at the IBM Thomas J. Watson Research Center. He was granted U.S. patent number 3,387,286 in 1968. Capacitors had been used for earlier memory schemes such as the drum of the Atanasoff–Berry Computer, the Williams tube and the Selectron tube.
Transistor
The first working silicon transistor was developed at Bell Labs on January 26, 1954 by Morris Tanenbaum. The first commercial silicon transistor was produced by Texas Instruments in 1954. This was the work of Gordon Teal, an expert in growing crystals of high purity, who had previously worked at Bell Labs. The first MOSFET actually built was by Kahng and Atalla at Bell Labs in 1960.
Caswell, Northamptonshire
The GaAs Field effect transistor and the GaAs monolithic ic were invented and developed at Caswell, but what is probably less well known is that scientists on the site were working on silicon integrated circuit(ic) technology almost 18 months before Jack Kilby demonstrated the first working ic at Texas Instruments in Dallas. 
Caswell technologists also developed the first multilayer ceramic capacitor and a host of other inventions that enabled many of the electronic products we rely on today – including mobile phones, satellite TV and WiFi.
Colpitts oscillator
A Colpitts oscillator, invented in 1918 by American engineer Edwin H. Colpitts, is one of a number of designs for LC oscillators, electronic oscillators that use a combination of inductors (L) and capacitors (C) to produce an oscillation at a certain frequency. The distinguishing feature of the Colpitts oscillator is that the feedback for the active device is taken from a voltage divider made of two capacitors in series across the inductor.
History of the transistor
The world’s first transistor computer was built at the University of Manchester in November 1953. The computer was built by Richard Grimsdale, then a research student in the Department of Electrical Engineering and later a Professor of Electronic Engineering at Sussex University. The machine used point-contact transistors, made in small quantities by STC and Mullard. These consisted of a single crystal of germanium with two fine wires, resembling the crystal and cat’s whisker of the 1920s. These transistors had the useful property that a single transistor could possess two stable states. ... The development of the machine was severely hampered by the unreliability of the transistors, which consumed 150 watts.
Propeller
In 1835, two inventors in Britain, John Ericsson and Francis Pettit Smith, began working separately on the problem. Smith was first to take out a screw propeller patent on 31 May, while Ericsson, a gifted Swedish engineer then working in Britain, filed his patent six weeks later. Smith quickly built a small model boat to test his invention, which was demonstrated first on a pond at his Hendon farm, and later at the Royal Adelaide Gallery of Practical Science in London, where it was seen by the Secretary of the Navy, Sir William Barrow. Having secured the patronage of a London banker named Wright, Smith then built a , canal boat of six tons burthen called "Francis Smith", which was fitted with a wooden propeller of his own design and demonstrated on the Paddington Canal from November 1836 to September 1837. By a fortuitous accident, the wooden propeller of two turns was damaged during a voyage in February 1837, and to Smith's surprise the broken propeller, which now consisted of only a single turn, doubled the boat's previous speed, from about four miles an hour to eight. Smith would subsequently file a revised patent in keeping with this accidental discovery.
Capacitor types
The most important group is the fixed capacitors. Many got their names from the dielectric. For a systematic classification these characteristics can't be used, because one of the oldest, the electrolytic capacitor, is named instead by its cathode construction. So the most-used names are simply historical.
Les Hoffman
The invention of the transistor in 1948 must have had an effect on Leslie Hoffman. In the early 1950s, he took a major interest in solar cells, also called photovoltaic cells. When Bell Labs introduced the solar cell to the world in 1951 it was only a curiosity. It had a very poor light-to-electricity conversion efficiency of 2 percent, and was very fragile and expensive to fabricate. Several manufacturers, including Hoffman, managed to improve the efficiency to 4.5 percent by 1954, but photovoltaic cells were still impractical.
Hoffman made great strides in making the solar cell a practical and useful source of renewable energy. From 1957 to 1960, he improved its efficiency from 4.5 to 14 percent and lowered the production cost to make it a marketable item. One of Hoffman's great achievements was the first satellite to be powered by solar cells, the Vanguard 1, launched in 1958. The solar arrays or panels are Hoffman photovoltaic cells. In 1959 H. Leslie Hoffman received the David Packard Medal of Achievement for innovation. In 1959 he was one of the board of directors for the Electronic Industries Association (EIA).
Insulated-gate bipolar transistor
IGBT mode of operation was first proposed by Yamagami in his Japanese patent S47-21739, which was filed in 1968. This mode of operation was first experimentally reported in the lateral four-layer device (SCR) by B. W. Scharf and J. D. Plummer in 1978. This mode of operation was also experimentally discovered in vertical device in 1979 by B. Jayant Baliga. The device structure was referred to as a "V-groove MOSFET device with the drain region replaced by a p-type anode region" in this paper and subsequently as "the insulated-gate rectifier" (IGR), the insulated-gate transistor (IGT), the conductivity-modulated field-effect transistor (COMFET) and "bipolar-mode MOSFET".
Water capacitor
Capacitors can originally be traced back to a device called a Leyden jar, created by the Dutch physicist Pieter van Musschenbroek. The Leyden jar consisted of a glass jar with tin foil layers on the inside and outside of the jar. A rod electrode was directly connected to the inlayer of foil by means of a small chain or wire. This device stored static electricity created when amber and wool where rubbed together.
Henri Tudor
Henri Owen Tudor (30 September 1859, in Ferschweiler – 31 May 1928) was a Luxembourgish engineer, inventor, and industrialist. He developed the first practical lead-acid battery in 1886 (Gaston Planté was the French physicist who invented the theoretical principle of a lead-acid battery in 1859).
Electrolytic capacitor
One of the first tantalum electrolytic capacitors were developed in 1930 by Tansitor Electronic Inc. USA, for military purposes. The basic construction of a wound cell was adopted and a tantalum anode foil was used together with a tantalum cathode foil, separated with a paper spacer impregnated with a liquid electrolyte, mostly sulfuric acid, and encapsulated in a silver case.
History of the transistor
Scientists theorized that silicon would be easier to fabricate, but few bothered to investigate this possibility. Morris Tanenbaum et al. at Bell Laboratories were the first to develop a working silicon transistor on January 26, 1954. A few months later, Gordon Teal, working independently at Texas Instruments, developed a similar device. Both of these devices were made by controlling the doping of single silicon crystals while they were grown from molten silicon. A far superior method was developed by Morris Tanenbaum and Calvin S. Fuller at Bell Laboratories in early 1955 by the gaseous diffusion of donor and acceptor impurities into single crystal silicon chips.
John Dixon Gibbs
John Dixon Gibbs (1834–1912) was a British engineer and financier who, together with Lucien Gaulard, is often credited as the co-inventor of the AC step-down transformer. The transformer was first demonstrated in 1883 at London's Royal Aquarium. At the time the term "transformer" had not yet been invented, so instead it was referred to as a "secondary generator". Although he is usually credited equally with Gaulard, Gibb's role in the invention appears to have been more that of a financial backer and businessman.
Electrolytic capacitor
The ancestor of the modern electrolytic capacitor was patented by Samuel Ruben in 1925, who teamed with Philip Mallory, the founder of the battery company that is now known as Duracell International. Ruben's idea adopted the stacked construction of a silver mica capacitor. He introduced a separated second foil to contact the electrolyte adjacent to the anode foil instead of using the electrolyte-filled container as the capacitor's cathode. The stacked second foil got its own terminal additional to the anode terminal and the container no longer had an electrical function. This type of electrolytic capacitor combined with an liquid or gel-like electrolyte of a non-aqueous nature, which is therefore dry in the sense of having a very low water content, became known as the "dry" type of electrolytic capacitor.
Capacitor
A capacitor can facilitate conversion of kinetic energy of charged particles into electric energy and store it.
History of the battery
In 1887, a dry-battery was developed by Yai Sakizō () of Japan, then patented in 1892. In 1893, Yai Sakizō's dry-battery was exhibited in World's Columbian Exposition and commanded considerable international attention.
Refrigerator
The history of artificial refrigeration began when Scottish professor William Cullen designed a small refrigerating machine in 1755. Cullen used a pump to create a partial vacuum over a container of diethyl ether, which then boiled, absorbing heat from the surrounding air. The experiment even created a small amount of ice, but had no practical application at that time.
In 1805, American inventor Oliver Evans described a closed vapor-compression refrigeration cycle for the production of ice by ether under vacuum. In 1820, the British scientist Michael Faraday liquefied ammonia and other gases by using high pressures and low temperatures, and in 1834, an American expatriate in Great Britain, Jacob Perkins, built the first working vapor-compression refrigeration system. It was a closed-cycle device that could operate continuously. A similar attempt was made in 1842, by American physician, John Gorrie, who built a working prototype, but it was a commercial failure. American engineer Alexander Twining took out a British patent in 1850 for a vapor compression system that used ether.
Capacitor
Daniel Gralath was the first to combine several jars in parallel to increase the charge storage capacity. Benjamin Franklin investigated the Leyden jar and came to the conclusion that the charge was stored on the glass, not in the water as others had assumed. He also adopted the term "battery", (denoting the increasing of power with a row of similar units as in a battery of cannon), subsequently applied to clusters of electrochemical cells. Leyden jars were later made by coating the inside and outside of jars with metal foil, leaving a space at the mouth to prevent arcing between the foils. The earliest unit of capacitance was the jar, equivalent to about 1.11 nanofarads.
Motor capacitor
for motor run capacitors
History of hearing aids
The development of transistors in 1948 by Bell Laboratories led to major improvements to the hearing aid. The transistor was invented by John Bardeen, Walter Brattain, and William Shockley. Transistors were created to replace vacuum tubes; they were small, required less battery power and had less distortion and heat than their predecessor. These vacuum tubes were typically hot and fragile, so the transistor was the ideal replacement.The 1952 Sonotone 1010 used a transistor stage along with vacuum tubes, to extend battery life. The size of these transistors led to developments in miniature, carbon microphones. These microphones could be mounted on various items, even eyeglasses. In 1951, Raytheon manufactured the transistor and was one of the first companies to mass-produce transistors to throughout America. Raytheon realized that their hearing aid only lasted short-term and began to sell the vacuum-tube hearing aids again along with transistor hearing aids.
History of the battery
In 1749, Benjamin Franklin, the U.S. polymath and founding father, first used the term "battery" to describe a set of linked capacitors he used for his experiments with electricity. These capacitors were panels of glass coated with metal on each surface. These capacitors were charged with a static generator and discharged by touching metal to their electrode. Linking them together in a "battery" gave a stronger discharge. Originally having the generic meaning of "a group of two or more similar objects functioning together", as in an artillery battery, the term came to be used for voltaic piles and similar devices in which many electrochemical cells were connected together in the manner of Franklin's capacitors. Today even a single electrochemical cell, e.g. a dry cell, is commonly called a battery.
Natterer compressor
The device was created by Johann Natterer, a student of Adolf Martin Pleischl, for experiments creating liquid carbonic acid.
Negative resistance
The negative impedance converter originated from work by Marius Latour around 1920. He was also one of the first to report negative capacitance and inductance. A decade later, vacuum tube NICs were developed as telephone line repeaters at Bell Labs by George Crisson and others, which made transcontinental telephone service possible. Transistor NICs, pioneered by Linvill in 1953, initiated a great increase in interest in NICs and many new circuits and applications developed.
Capacitor types
Beneath the above described capacitors covering more or less nearly the total market of discrete capacitors some new developments or very special capacitor types as well as older types can be found in electronics.
Capacitor plague
Industrial espionage was implicated in the capacitor plague, in connection with the theft of an electrolyte formula. A materials scientist working for Rubycon in Japan left the company, taking the secret water-based electrolyte formula for Rubycon's ZA and ZL series capacitors, and began working for a Chinese company. The scientist then developed a copy of this electrolyte. Then, some staff members who defected from the Chinese company copied an incomplete version of the formula and began to market it to many of the aluminium electrolytic manufacturers in Taiwan, undercutting the prices of the Japanese manufacturers. This incomplete electrolyte lacked important proprietary ingredients which were essential to the long-term stability of the capacitors and was unstable when packaged in a finished aluminum capacitor. This faulty electrolyte allowed the unimpeded formation of hydroxide and produced hydrogen gas.
EPROM
Development of the EPROM memory cell started with investigation of faulty integrated circuits where the gate connections of transistors had broken. Stored charge on these isolated gates changed their properties. The EPROM was invented by Dov Frohman of Intel in 1971, who was awarded US patent 3660819 in 1972.
Each storage location of an EPROM consists of a single field-effect transistor. Each field-effect transistor consists of a channel in the semiconductor body of the device. Source and drain contacts are made to regions at the end of the channel. An insulating layer of oxide is grown over the channel, then a conductive (silicon or aluminum) gate electrode is deposited, and a further thick layer of oxide is deposited over the gate electrode. The floating-gate electrode has no connections to other parts of the integrated circuit and is completely insulated by the surrounding layers of oxide. A control gate electrode is deposited and further oxide covers it.
SAL electrolytic capacitor
SAL-capacitors were developed and introduced in the market in the 1960s by Philips. Up until December 30, 2015, it was a single source product manufactured by Vishay. As of December 31, 2015 these are now end-of-life and have ceased production.
Electrolytic capacitor
These first sintered tantalum capacitors used a non-solid electrolyte, which does not fit the concept of solid electronics. In 1952 a targeted search at Bell Labs by D. A. McLean and F. S. Power for a solid electrolyte led to the invention of manganese dioxide as a solid electrolyte for a sintered tantalum capacitor.
Julius Edgar Lilienfeld
In the United States Lilienfeld did research on anodic aluminum oxide films, patenting the electrolytic capacitor in 1931, the method continuing to be used throughout the century. He also invented an "FET-like" transistor, filing several patents describing the construction and operation of transistors, as well as many features of modern transistors. (US patent #1,745,175 for an FET-like transistor was granted January 28, 1930.) When Brattain, Bardeen, and their colleague chemist Robert Gibney tried to get patents on their earliest devices, most of their claims were rejected due to the Lilienfeld patents.
Variable capacitor
The variable capacitor with air dielectric was invented by the Hungarian engineer Dezső Korda. He received a German patent for the invention on 13 December 1893.
The thickness of the depletion layer of a reverse-biased semiconductor diode varies with the DC voltage applied across the diode. Any diode exhibits this effect (including p/n junctions in transistors), but devices specifically sold as variable capacitance diodes (also called varactors or varicaps) are designed with a large junction area and a doping profile specifically designed to maximize capacitance.
Single-atom transistor
A single-atom transistor is a device that can open and close an electrical circuit by the controlled and reversible repositioning of one single atom. The single-atom transistor was invented and first demonstrated in 2004 by Prof. Thomas Schimmel and his team of scientists at the Karlsruhe Institute of Technology (former University of Karlsruhe). By means of a small electrical voltage applied to a control electrode, the so-called "gate electrode", a single silver atom is reversibly moved in and out of a tiny junction, in this way closing and opening an electrical contact.
Distributor
The first reliable battery operated ignition was developed by Dayton Engineering Laboratories Co. (Delco) and introduced in the 1910 Cadillac. This ignition was developed by Charles Kettering and was considered a wonder in its day. Atwater Kent invented his Unisparker ignition system about this time in competition with the Delco system. By the end of the 20th century mechanical ignitions were disappearing from automotive applications in favor of inductive or capacitive electronic ignitions fully controlled by engine control units (ECU), rather than directly timed to the engine's crankshaft speed.
Carburetor
Frederick William Lanchester of Birmingham, England, experimented with the wick carburetor in cars. In 1896, Frederick and his brother built a gasoline-driven car in England, a single cylinder internal combustion engine with chain drive. Unhappy with the car's performance and power, they re-designed the engine the following year using two horizontally-opposed cylinders and a newly designed wick carburetor.
History of the battery
Volta's original pile models had some technical flaws, one of them involving the electrolyte leaking and causing short-circuits due to the weight of the discs compressing the brine-soaked cloth. A Scotsman named William Cruickshank solved this problem by laying the elements in a box instead of piling them in a stack. This was known as the trough battery. Volta himself invented a variant that consisted of a chain of cups filled with a salt solution, linked together by metallic arcs dipped into the liquid. This was known as the Crown of Cups. These arcs were made of two different metals (e.g., zinc and copper) soldered together. This model also proved to be more efficient than his original piles, though it did not prove as popular.
Polymer capacitor
Tantalum electrolytic capacitors with solid manganese dioxide (MnO) electrolytes were invented by Bell Laboratories in the early 1950s, as a miniaturized and more reliable low-voltage support capacitor to complement the newly invented transistor, see Tantalum capacitor. The first Ta-e-caps with MnO electrolytes had 10 times better conductivity and a higher ripple current load than earlier types Al-e-caps with liquid electrolyte. Additionally, unlike standard Al-e-caps, the equivalent series resistance (ESR) of Ta-caps is stable in varying temperatures.
Farad
A capacitor generally consists of two conducting surfaces, frequently referred to as plates, separated by an insulating layer usually referred to as a dielectric. The original capacitor was the Leyden jar developed in the 18th century. It is the accumulation of electric charge on the plates that results in capacitance. Modern capacitors are constructed using a range of manufacturing techniques and materials to provide the extraordinarily wide range of capacitance values used in electronics applications from femtofarads to farads, with maximum-voltage ratings ranging from a few volts to several kilovolts.
2N107
The 2N107 was conceived in 1955 by Carl David Todd, who had just joined GE as an engineer. Todd's interest in a hobby/experimental transistor probably originated when he participated in one of the CK722 transistor design contests, while he was an engineering student at Auburn University and finished sixth. The success of the CK722 gave impetus for Carl Todd to convince GE marketing to follow the path of Raytheon, the inventor of the CK722. General Electric had a lot of 2N43 thru 2N45 type transistors that did not meet specifications. Like Norman Krim at Raytheon, Carl Todd wanted to increase GE's transistor market by expanding into the hobbyist market.
Capacitor
A light-emitting capacitor is made from a dielectric that uses phosphorescence to produce light. If one of the conductive plates is made with a transparent material, the light is visible. Light-emitting capacitors are used in the construction of electroluminescent panels, for applications such as backlighting for laptop computers. In this case, the entire panel is a capacitor used for the purpose of generating light.
Benjamin Franklin Bailey
He became professor of electrical engineering at the University of Michigan in 1913 and was department chairman from 1922 until his retirement in 1944. In the 1920s, he invented the capacitor motor.
Refrigerator
In 1913, refrigerators for home and domestic use were invented by Fred W. Wolf of Fort Wayne, Indiana, with models consisting of a unit that was mounted on top of an ice box. In 1914, engineer Nathaniel B. Wales of Detroit, Michigan, introduced an idea for a practical electric refrigeration unit, which later became the basis for the Kelvinator. A self-contained refrigerator, with a compressor on the bottom of the cabinet was invented by Alfred Mellowes in 1916. Mellowes produced this refrigerator commercially but was bought out by William C. Durant in 1918, who started the Frigidaire company to mass-produce refrigerators. In 1918, Kelvinator company introduced the first refrigerator with any type of automatic control. The absorption refrigerator was invented by Baltzar von Platen and Carl Munters from Sweden in 1922, while they were still students at the Royal Institute of Technology in Stockholm. It became a worldwide success and was commercialized by Electrolux. Other pioneers included Charles Tellier, David Boyle, and Raoul Pictet. Carl von Linde was the first to patent and make a practical and compact refrigerator.
Electrical reactance
A capacitor consists of two conductors separated by an insulator, also known as a dielectric.
Capacitor
Since the beginning of the study of electricity non conductive materials like glass, porcelain, paper and mica have been used as insulators. These materials some decades later were also well-suited for further use as the dielectric for the first capacitors. 
Paper capacitors made by sandwiching a strip of impregnated paper between strips of metal, and rolling the result into a cylinder were commonly used in the late 19th century; their manufacture started in 1876, and they were used from the early 20th century as decoupling capacitors in telecommunications (telephony).
Electrolytic capacitor
Charles Pollak (born Karol Pollak), a producer of accumulators, found out that the oxide layer on an aluminum anode remained stable in a neutral or alkaline electrolyte, even when the power was switched off. In 1896 he filed a patent for an "Electric liquid capacitor with aluminum electrodes" (de: "Elektrischer Flüssigkeitskondensator mit Aluminiumelektroden") based on his idea of using the oxide layer in a polarized capacitor in combination with a neutral or slightly alkaline electrolyte.
Induction coil
Michael Faraday discovered the principle of induction, Faraday's induction law, in 1831 and did the first experiments with induction between coils of wire. The induction coil was invented by the American physician Charles Grafton Page in 1836 and independently by Irish scientist and Catholic priest Nicholas Callan in the same year at the St. Patrick's College, Maynooth and improved by William Sturgeon. George Henry Bachhoffner and Sturgeon (1837) independently discovered that a "divided" iron core of iron wires reduced power losses. The early coils had hand cranked interrupters, invented by Callan and Antoine Philibert Masson (1837). The automatic 'hammer' interrupter was invented by Rev. Prof. James William MacGauley (1838) of Dublin, Ireland, Johann Philipp Wagner (1839), and Christian Ernst Neeff (1847). Hippolyte Fizeau (1853) introduced the use of the quenching capacitor. Heinrich Ruhmkorff generated higher voltages by greatly increasing the length of the secondary, in some coils using 5 or 6 miles (10 km) of wire and produced sparks up to 16 inches. In the early 1850s, American inventor Edward Samuel Ritchie introduced the divided secondary construction to improve insulation. Jonathan Nash Hearder worked on induction coils. Callan's induction coil was named an IEEE Milestone in 2006.
Bell Labs
In 1947, the transistor, probably the most important invention developed by Bell Laboratories, was invented by John Bardeen, Walter Houser Brattain, and William Bradford Shockley (and who subsequently shared the Nobel Prize in Physics in 1956). In 1947, Richard Hamming invented Hamming codes for error detection and correction. For patent reasons, the result was not published until 1950. In 1948, "A Mathematical Theory of Communication", one of the founding works in information theory, was published by Claude Shannon in the "Bell System Technical Journal". It built in part on earlier work in the field by Bell researchers Harry Nyquist and Ralph Hartley, but it greatly extended these. Bell Labs also introduced a series of increasingly complex calculators through the decade. Shannon was also the founder of modern cryptography with his 1949 paper "Communication Theory of Secrecy Systems".In 1952, William Gardner Pfann revealed the method of zone melting which enabled semiconductor purification and level doping.
Film capacitor
The "film capacitors" were developed together with the growing market of broadcast and electronic equipment technology in the mid-20th century. These capacitors are standardized under the rules of IEC/EN 60384-1 “Capacitors for use in electronic equipment” and different "film materials" have their own sub standards, the IEC/EN 60384-"n" series. The "power capacitors" begin at a power handling capacity of approximately 200 volt-amps, such as for ballast capacitors in fluorescent lamps. The standardization of power capacitors follows the rules of IEC/EN 61071 and IEC/EN 60143-1, and have for various different applications their own sub standards, such as for railway applications.
Leyden jar
By the middle of the 19th century, the Leyden jar had become common enough for writers to assume their readers knew of and understood its basic operation. Around the turn of the century it began to be widely used in spark-gap transmitters and medical electrotherapy equipment. By the early 20th century, improved dielectrics and the need to reduce their size and undesired inductance and resistance for use in the new technology of radio caused the Leyden jar to evolve into the modern compact form of capacitor.
Taiyo Yuden
The world's first axial leaded ceramic capacitor is developed by company in July 1976.
List of Dutch inventions and innovations
A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a glass jar. It was the original form of a capacitor (originally known as a "condenser"). It was invented independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden) in 1745–1746. The invention was named for the city. The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electricity. Previously, researchers had to resort to insulated conductors of large dimensions to store a charge. The Leyden jar provided a much more compact alternative. Like many early electrical devices, there was no particular use for the Leyden jar at first, other than to allow scientists to do a greater variety of electrical experiments. Benjamin Franklin, for example, used a Leyden jar to store electricity from lightning in his famous kite experiment in 1752. By doing so he proved that lightning was really electricity.
William Dubilier
William Dubilier (July 25, 1888 – July 25, 1969) was an American inventor in the field of radio and electronics. He demonstrated radio communication at Seattle's Alaska-Yukon-Pacific Exposition on June 21, 1909; ten years before the first commercial station operated. A graduate of Cooper Union, he was the first to use sheets of naturally occurring mica as the dielectric in a capacitor. Mica capacitors were widely used in early radio oscillator and tuning circuits because the temperature coefficient of expansion of mica was low, resulting in very stable capacitance – mica capacitors are still used where exceptional temperature stability is needed.
History of electric power transmission
When George Westinghouse became interested in electricity, he quickly and correctly concluded that Edison's low voltages were too inefficient to be scaled up for transmission needed for large systems. He further understood that long-distance transmission needed high voltage and that inexpensive conversion technology only existed for alternating current. Transformers would play the decisive role in the victory of alternating current over direct current for transmission and distribution systems. In 1876, Pavel Yablochkov patented his mechanism of using induction coils to serve as a step up transformer prior to the Paris Exposition demonstrating his arc lamps. In 1881, Lucien Gaulard and John Dixon Gibbs developed a more efficient device which they dubbed the secondary generator, namely an early transformer provided with 1:1 turn ratio and open magnetic circuit.
The first demonstrative long distance (34 km, i.e. 21 mi) AC line was built for the 1884 International Exhibition of Turin, Italy. It was powered by a 2-kV, 130-Hz Siemens & Halske alternator and featured several Gaulard secondary generators with their primary windings connected in series, which fed incandescent lamps. The system proved the feasibility of AC electric power transmission on long distances. After this success, between 1884 and 1885, Hungarian engineers Zipernowsky, Bláthy, and Déri from the Ganz company in Budapest created the efficient "Z.B.D." closed-core coils, as well as the modern electric distribution system. The three had discovered that all former coreless or open-core devices were incapable of regulating voltage, and were therefore impractical. Their joint patent described two versions of a design with no poles: the "closed-core transformer" and the "shell-core transformer". Ottó Bláthy suggested the use of closed-cores, Károly Zipernowsky the use of shunt connections, and Miksa Déri performed the experiments.
Capacitor
Porcelain was used in the first ceramic capacitors. In the early years of Marconi's wireless transmitting apparatus porcelain capacitors were used for high voltage and high frequency application in the transmitters. On the receiver side smaller mica capacitors were used for resonant circuits. Mica dielectric capacitors were invented in 1909 by William Dubilier. Prior to World War II, mica was the most common dielectric for capacitors in the United States.
Sprague Electric
Sprague used $25,000 of his savings to open Sprague Specialties Company at his home in Quincy, MA, in 1926. One of his first products was the mini condenser (an old name for capacitor). Mini condensers were commonly used in radio applications for noise filtering, signal coupling and tone controls. Early capacitors were two pieces of metal foil wrapped between wax paper or any other type of suitable insulation material. The type of insulating material determined the capacitor's capacitance and maximum voltage. Capacitors are also useful in high power applications like motors, and soon Sprague turned his attention those areas as well.
LC circuit
The first evidence that a capacitor and inductor could produce electrical oscillations was discovered in 1826 by French scientist Felix Savary. He found that when a Leyden jar was discharged through a wire wound around an iron needle, sometimes the needle was left magnetized in one direction and sometimes in the opposite direction. He correctly deduced that this was caused by a damped oscillating discharge current in the wire, which reversed the magnetization of the needle back and forth until it was too small to have an effect, leaving the needle magnetized in a random direction. American physicist Joseph Henry repeated Savary's experiment in 1842 and came to the same conclusion, apparently independently. British scientist William Thomson (Lord Kelvin) in 1853 showed mathematically that the discharge of a Leyden jar through an inductance should be oscillatory, and derived its resonant frequency. British radio researcher Oliver Lodge, by discharging a large battery of Leyden jars through a long wire, created a tuned circuit with its resonant frequency in the audio range, which produced a musical tone from the spark when it was discharged. In 1857, German physicist Berend Wilhelm Feddersen photographed the spark produced by a resonant Leyden jar circuit in a rotating mirror, providing visible evidence of the oscillations. In 1868, Scottish physicist James Clerk Maxwell calculated the effect of applying an alternating current to a circuit with inductance and capacitance, showing that the response is maximum at the resonant frequency. The first example of an electrical resonance curve was published in 1887 by German physicist Heinrich Hertz in his pioneering paper on the discovery of radio waves, showing the length of spark obtainable from his spark-gap LC resonator detectors as a function of frequency.
MOSFET
In 1959, Dawon Kahng and Martin M. (John) Atalla at Bell Labs invented the metal-oxide-semiconductor field-effect transistor (MOSFET) as an offshoot to the patented FET design. Operationally and structurally different from the bipolar junction transistor, the MOSFET was made by putting an insulating layer on the surface of the semiconductor and then placing a metallic gate electrode on that. It used crystalline silicon for the semiconductor and a thermally oxidized layer of silicon dioxide for the insulator. The silicon MOSFET did not generate localized electron traps at the interface between the silicon and its native oxide layer, and thus was inherently free from the trapping and scattering of carriers that had impeded the performance of earlier field-effect transistors.
Supercapacitor
Early electrochemical capacitors used two aluminum foils covered with activated carbon—the electrodes—which were soaked in an electrolyte and separated by a thin porous insulator. This design gave a capacitor with a capacitance on the order of one farad, significantly higher than electrolytic capacitors of the same dimensions. This basic mechanical design remains the basis of most electrochemical capacitors.
Electrolytic capacitor
Although fundamental inventions came from Bell Labs, the inventions for manufacturing commercially viable tantalum electrolytic capacitors came from researchers at the Sprague Electric Company. Preston Robinson, Sprague's Director of Research, is considered to be the actual inventor of tantalum capacitors in 1954. His invention was supported by R. J. Millard, who introduced the "reform" step in 1955, a significant improvement in which the dielectric of the capacitor was repaired after each dip-and-convert cycle of MnO deposition, which dramatically reduced the leakage current of the finished capacitors.
Captopril
Captopril was discovered in 1977. It was the first ACE inhibitor developed and was considered a breakthrough both because of its novel mechanism of action and also because of the revolutionary development process. Captopril was discovered and developed at E. R. Squibb & Sons Pharmaceuticals based on concepts pioneered by Nobel Laureate John Vane and is now marketed by Bristol-Myers Squibb.
Water capacitor
Conventional capacitors use materials such as glass or ceramic as their insulating medium to store an electric charge. Water capacitors were created mainly as a novelty item or for laboratory experimentation, and can be made with simple materials.
Water exhibits the quality of being self-healing; if there is an electrical breakdown through the water, it quickly returns to its original and undamaged state. Other liquid insulators are prone to carbonization after breakdown, and tend to lose their hold off strength over time.
History of the transistor
The first patent for the field-effect transistor principle was filed in Canada by Austrian-Hungarian physicist Julius Edgar Lilienfeld on October 22, 1925, but Lilienfeld published no research articles about his devices, and his work was ignored by industry. In 1934 German physicist Dr. Oskar Heil patented another field-effect transistor. There is no direct evidence that these devices were built, but later work in the 1990s show that one of Lilienfeld's designs worked as described and gave substantial gain. Legal papers from the Bell Labs patent show that William Shockley and a co-worker at Bell Labs, Gerald Pearson, had built operational versions from Lilienfeld's patents, yet they never referenced this work in any of their later research papers or historical articles.
The Bell Labs work on the transistor emerged from war-time efforts to produce extremely pure germanium "crystal" mixer diodes, used in radar units as a frequency mixer element in microwave radar receivers. A parallel project on germanium diodes at Purdue University succeeded in producing the good-quality germanium semiconducting crystals that were used at Bell Labs. Early tube-based circuits did not switch fast enough for this role, leading the Bell team to use solid state diodes instead.
Niobium capacitor
Niobium capacitors were developed in the United States as well as in the Soviet Union in the 1960s. Since 2002 they have been commercially available in the West to take advantage of the lower cost and better availability of niobium compared with tantalum.
Two capacitor paradox
The two capacitor paradox or capacitor paradox is a paradox, or counterintuitive thought experiment, in electric circuit theory. The thought experiment is usually described as follows: 
Two identical capacitors are connected in parallel with an open switch between them. One of the capacitors is charged with a voltage of formula_1, the other is uncharged. When the switch is closed, some of the charge formula_2 on the first capacitor flows into the second, reducing the voltage on the first and increasing the voltage on the second. When a steady state is reached and the current goes to zero, the voltage on the two capacitors must be equal since they are connected together. Since they both have the same capacitance formula_3 the charge will be divided equally between the capacitors so each capacitor will have a charge of formula_4 and a voltage of formula_5. At the beginning of the experiment the total initial energy formula_6 in the circuit is the energy stored in the charged capacitor: 
At the end of the experiment the final energy formula_8 is equal to the sum of the energy in the two capacitors 
Thus the final energy formula_8 is equal to half of the initial energy formula_6. Where did the other half of the initial energy go?
Capacitor
The simplest model capacitor consists of two thin parallel conductive plates each with an area of formula_3 separated by a uniform gap of thickness formula_4 filled with a dielectric with permittivity formula_5. It is assumed the gap formula_4 is much smaller than the dimensions of the plates. This model applies well to many practical capacitors which are constructed of metal sheets separated by a thin layer of insulating dielectric, since manufacturers try to keep the dielectric very uniform in thickness to avoid thin spots which can cause failure of the capacitor.
Tantalum capacitor
Although the fundamental inventions came from the Bell Labs, the innovations for manufacturing commercially viable tantalum electrolytic capacitors were done by the researchers of the Sprague Electric Company. Preston Robinson, Sprague's Director of Research, is considered to be the actual inventor of tantalum capacitors in 1954. His invention was supported by R. J. Millard, who introduced the “reform” step in 1955, a significant improvement in which the dielectric of the capacitor was repaired after each dip-and-convert cycle of MnO deposition. This dramatically reduced the leakage current of the finished capacitors.
Capacitor discharge ignition
This was put into practice starting in 1906 on the Ford Model K. The Model K had dual ignition systems, one of which was the Holley-Huff Magneto, or Huff System, manufactured by the Holley Brothers Company. It was designed by Edward S. Huff with US patent #882003 filed July 1, 1905 and assigned to Henry Ford. The system used an engine driven DC generator that charged a capacitor and then discharged the capacitor through the ignition coil primary winding. An excerpt from the 'Motorway' Jan 11 1906, describes its use on Ford six cylinder cars: 'The efficiency of the Ford Magneto is shown by the fact that the instant it is switched in the car will pick up speed and, without changing the position of the ignition control lever, will run at least ten miles an hour faster.'
Intel 1103
In 1969 William Regitz and his colleagues at Honeywell invented a three-transistor dynamic memory cell and began to canvass the semiconductor industry for a producer. The recently founded Intel Corporation responded and developed two very similar 1024-bit chips, the 1102 and 1103, under the lead of Joel Karp, working closely with William Regitz. Ultimately only the 1103 went into production.
Electrolytic capacitor
William Dubilier, whose first patent for electrolytic capacitors was filed in 1928, industrialized the new ideas for electrolytic capacitors and started the first large commercial production in 1931 in the Cornell-Dubilier (CD) factory in Plainfield, New Jersey. At the same time in Berlin, Germany, the "Hydra-Werke", an AEG company, started the production of e-caps in large quantities.
In his 1896 patent Pollak already recognized that the capacitance of the capacitor increases when roughening the surface of the anode foil. Today (2014), electrochemically etched low voltage foils can achieve an up to 200-fold increase in surface area compared to a smooth surface. Advances in the etching process are the reason for the dimension reductions in aluminum electrolytic capacitors over recent decades.
Aluminum electrolytic capacitor
The development of tantalum electrolytic capacitors in the early 1950s with manganese dioxide as solid electrolyte, which has a 10 times better conductivity than all other types of non-solid electrolytes, also influenced the development of aluminum electrolytic capacitors. In 1964 the first aluminum electrolytic capacitors with solid electrolyte (Solid aluminum capacitor (SAL)) appeared on the market, developed by Philips.
Leyden jar
A Leyden jar (or Leiden jar) stores a high-voltage electric charge (from an external source) between electrical conductors on the inside and outside of a glass jar. A Leyden jar 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 the capacitor (also called "condenser").
Transistor
In 1948, the point-contact transistor was independently invented by German physicists Herbert Mataré and Heinrich Welker while working at the "Compagnie des Freins et Signaux", a Westinghouse subsidiary located in Paris. Mataré had previous experience in developing crystal rectifiers from silicon and germanium in the German radar effort during World War II. Using this knowledge, he began researching the phenomenon of "interference" in 1947. By June 1948, witnessing currents flowing through point-contacts, Mataré produced consistent results using samples of germanium produced by Welker, similar to what Bardeen and Brattain had accomplished earlier in December 1947. Realizing that Bell Labs' scientists had already invented the transistor before them, the company rushed to get its "transistron" into production for amplified use in France's telephone network.
History of electronic engineering
Vacuum tubes remained the preferred amplifying device for 40 years, until researchers working for William Shockley at Bell Labs invented the transistor in 1947. In the following years, transistors made small portable radios, or transistor radios, possible as well as allowing more powerful mainframe computers to be built. Transistors were smaller and required lower voltages than vacuum tubes to work.
Transistor
The thermionic triode, a vacuum tube invented in 1907, enabled amplified radio technology and long-distance telephony. The triode, however, was a fragile device that consumed a substantial amount of power. In 1909 physicist William Eccles discovered the crystal diode oscillator. Physicist Julius Edgar Lilienfeld filed a patent for a field-effect transistor (FET) in Canada in 1925 , which was intended to be a solid-state replacement for the triode. Lilienfeld also filed identical patents in the United States in 1926 and 1928. However, Lilienfeld did not publish any research articles about his devices nor did his patents cite any specific examples of a working prototype. Because the production of high-quality semiconductor materials was still decades away, Lilienfeld's solid-state amplifier ideas would not have found practical use in the 1920s and 1930s, even if such a device had been built. In 1934, German inventor Oskar Heil patented a similar device in Europe.
Supercapacitor
In the early 1950s, General Electric engineers began experimenting with porous carbon electrodes, in the design of capacitors, from the design of fuel cells and rechargeable batteries. Activated charcoal is an electrical conductor that is an extremely porous "spongy" form of carbon with a high specific surface area. In 1957 H. Becker developed a "Low voltage electrolytic capacitor with porous carbon electrodes". He believed that the energy was stored as a charge in the carbon pores as in the pores of the etched foils of electrolytic capacitors. Because the double layer mechanism was not known by him at the time, he wrote in the patent: "It is not known exactly what is taking place in the component if it is used for energy storage, but it leads to an extremely high capacity."
Polymer capacitor
A breakthrough came in 1973, with the discovery by A. Heeger and F. Wudl of an organic conductor, the charge-transfer salt TCNQ. TCNQ (7,7,8,8-tetracyanoquinodimethane or N-n-butyl isoquinolinium in combination with TTF (Tetrathiafulvalene)) is a chain molecule of almost perfect one-dimensional structure that has a 10-fold better conductivity along the chains than does MnO, and has a 100-fold better conductivity than non-solid electrolytes.
Condenser (laboratory)
The condenser known as the Liebig type, a most basic circulating fluid-cooled design, was invented by several investigators working independently; however, the earliest laboratory condenser was invented in 1771 by the Swedish-German chemist Christian Weigel (1748–1831). Weigel’s condenser consisted of two coaxial tin tubes, which were joined at their lower ends and open at their upper ends. Cold water entered, via an inlet, the lower end of this jacket and spilled out of the jacket’s open upper end. A glass tube carrying vapors from a distillation flask passed through the inner tin tube, not in contact with the cooling water. Weigel subsequently replaced the inner tin tube with a glass tube, and he devised a clamp to hold the condenser. In 1791, the German chemist Johann Friedrich August Göttling (1753–1809), who was a former student of Weigel, sealed both ends of Weigel's condenser. The German chemist Justus Liebig (1803–1873) eliminated the inner wall of Weigel’s condenser, placing, in direct contact with the jacket’s cooling water, the glass tube carrying vapors from the distillation flask. He also replaced, with glass, the outer metal wall of Weigel’s condenser. And he used rubber hoses, instead of metal tubes, to convey water to and from the condenser.
Loading coil
Pupin's 1894 patent "loads" the line with capacitors rather than inductors, a scheme that has been criticised as being theoretically flawed and never put into practice. To add to the confusion, one variant of the capacitor scheme proposed by Pupin does indeed have coils. However, these are not intended to compensate the line in any way. They are there merely to restore DC continuity to the line so that it may be tested with regular equipment. Pupin states that the inductance is to be so large that it will block all AC signals above 50 Hz. Consequently, only the capacitor is adding any significant impedance to the line and "the coils will not exercise any material influence on the results before noted".
Heaviside never patented his idea; indeed, he took no commercial advantage of any of his work. Despite the legal disputes surrounding this invention, it is unquestionable that Campbell was the first to actually construct a telephone circuit using loading coils. There also can be little doubt that Heaviside was the first to publish and many would dispute Pupin's priority.
Experiments and Observations on Electricity
Franklin's first experiments explained in this first set of letters to Collinson that the Leyden jar, a type of capacitor, had equal and opposite charges on the inner and outer conductors. This was shown in illustrations in his book. The significant Franklin theory introduced to Collinson in a letter dated April 29, 1747, was the concept of the "dissectible condenser." Today we call this distribution of charges in a device, a capacitor. He observed that a charge was built up on both sides between a piece of nonconducting material. In the case of the Leyden jar this was glass (nonconducting matter) and on each side of it was a metal material (conducting matter). These opposite metal layers had the exact opposite electric charges (positive and negative). He observed that when the wire on the inside of the jar was "electrised" positively by a certain amount, that the outer conductor simultaneously became "electrised" negatively in the same proportion.
Detonator
In 1875, H. Julius Smith—and then in 1887, Perry G. Gardner of North Adams, Massachusetts—developed electric detonators that combined a hot wire detonator with mercury fulminate explosive. These were the first generally modern type blasting caps. Modern caps use different explosives and separate primary and secondary explosive charges, but are generally very similar to the Gardner and Smith caps.
Supercapacitor
At the end of the 1980s, improved electrode materials increased capacitance values. At the same time, the development of electrolytes with better conductivity lowered the equivalent series resistance (ESR) increasing charge/discharge currents. The first supercapacitor with low internal resistance was developed in 1982 for military applications through the Pinnacle Research Institute (PRI), and were marketed under the brand name "PRI Ultracapacitor". In 1992, Maxwell Laboratories (later Maxwell Technologies) took over this development. Maxwell adopted the term Ultracapacitor from PRI and called them "Boost Caps" to underline their use for power applications.
Analog-to-digital converter
The Wilkinson ADC was designed by D. H. Wilkinson in 1950. The Wilkinson ADC is based on the comparison of an input voltage with that produced by a charging capacitor. The capacitor is allowed to charge until its voltage is equal to the amplitude of the input pulse (a comparator determines when this condition has been reached). Then, the capacitor is allowed to discharge linearly, which produces a ramp voltage. At the point when the capacitor begins to discharge, a gate pulse is initiated. The gate pulse remains on until the capacitor is completely discharged. Thus the duration of the gate pulse is directly proportional to the amplitude of the input pulse. This gate pulse operates a linear gate which receives pulses from a high-frequency oscillator clock. While the gate is open, a discrete number of clock pulses pass through the linear gate and are counted by the address register. The time the linear gate is open is proportional to the amplitude of the input pulse, thus the number of clock pulses recorded in the address register is proportional also. Alternatively, the charging of the capacitor could be monitored, rather than the discharge.
RLC circuit
The first evidence that a capacitor could produce electrical oscillations was discovered in 1826 by French scientist Felix Savary. He found that when a Leyden jar was discharged through a wire wound around an iron needle, sometimes the needle was left magnetized in one direction and sometimes in the opposite direction. He correctly deduced that this was caused by a damped oscillating discharge current in the wire, which reversed the magnetization of the needle back and forth until it was too small to have an effect, leaving the needle magnetized in a random direction.
Water capacitor
Although the design and materials used in capacitors have changed greatly throughout history, the basic fundamentals remain the same. In general, capacitors are very simple electrical devices which can have many uses in today's technologically advanced world. A modern capacitor usually consists of two conducting plates sandwiched around an insulator. Electrical researcher Nicola Tesla described capacitors as the "electrical equivalent of dynamite".
János Csonka
János Csonka (1852 in Szeged – 1939 in Budapest) was a Hungarian engineer, the co-inventor of the carburetor for the stationary engine with Donát Bánki, patented on 13 February 1893.
Csonka, self-educated in many fields, had no university degree, but became one of the greatest figures of Hungarian engineering industry, and with the carburetor he has heavily contributed to technical development in the world. He studied the Lenoir motor in Paris in 1874 and there he recognized the prospects of the internal combustion engine.
He became head of the training workshop at the Technical University of Budapest at the age of 25 where he employed skilled workers at his own expense, which allowed him to use the workshop for his experiments.
Csonka retired at the age of 73 and filed his last patent application at the age of 84.
Power electronics
In 1947 the bipolar point-contact transistor was invented by Walter H. Brattain and John Bardeen under the direction of William Shockley at Bell Labs. In 1948 Shockley's invention of the bipolar junction transistor (BJT) improved the stability and performance of transistors, and reduced costs. By the 1950s, higher power semiconductor diodes became available and started replacing vacuum tubes. In 1956 the silicon controlled rectifier (SCR) was introduced by General Electric, greatly increasing the range of power electronics applications.
Capacitor
In October 1745, Ewald Georg von Kleist of Pomerania, Germany, found that charge could be stored by connecting a high-voltage electrostatic generator by a wire to a volume of water in a hand-held glass jar. Von Kleist's hand and the water acted as conductors, and the jar as a dielectric (although details of the mechanism were incorrectly identified at the time). Von Kleist found that touching the wire resulted in a powerful spark, much more painful than that obtained from an electrostatic machine. The following year, the Dutch physicist Pieter van Musschenbroek invented a similar capacitor, which was named the Leyden jar, after the University of Leiden where he worked. He also was impressed by the power of the shock he received, writing, "I would not take a second shock for the kingdom of France."
History of electromagnetic theory
There are a range of emerging energy technologies. By 2007, solid state micrometer-scale electric double-layer capacitors based on advanced superionic conductors had been for low-voltage electronics such as deep-sub-voltage nanoelectronics and related technologies (the 22 nm technological node of CMOS and beyond). Also, the nanowire battery, a lithium-ion battery, was invented by a team led by Dr. Yi Cui in 2007.
Carburetor
A carburetor was among the early patents by Karl Benz (1888) as he developed internal combustion engines and their components.
Electrolytic capacitor
) from a 1976 data sheet
Leclanché cell
The Leclanché cell is a battery invented and patented by the French scientist Georges Leclanché in 1866. The battery contained a conducting solution (electrolyte) of ammonium chloride, a cathode (positive terminal) of carbon, a depolarizer of manganese dioxide (oxidizer), and an anode (negative terminal) of zinc (reductant). The chemistry of this cell was later successfully adapted to manufacture a dry cell.
Hippolyte Fizeau
In 1853, Fizeau described the use of the capacitor (sometimes called a "condenser") as a means to increase the efficiency of the induction coil. Later on, he studied the thermal expansion of solids and applied the phenomenon of interference of light to the measurement of the dilatations of crystals. He became a member of the Académie des Sciences in 1860 and a member of the Bureau des Longitudes in 1878. He died at Venteuil on 18 September 1896.
Gyrator
corresponding to the introduction of a series capacitor
Dubilier Condenser Company
The Dubilier Condenser Company was the earliest commercial manufacturer of electronic capacitors, formerly known as condensers, which were widely used in early radio receivers (wireless sets). The company was founded in New York in 1920, by William Dubilier, who was responsible for many early developments in the field of electronics and radio, including the use of mica in capacitors. Dubilier was a name commonly found on capacitors in early wireless sets in Britain alongside TCC, Wima, and others. Dubilier Condenser was later merged into Cornell Dubilier.
Ceramic capacitor
Even in the early years of Marconi's wireless transmitting apparatus, porcelain capacitors were used for high voltage and high frequency application in the transmitters. On the receiver side, the smaller mica capacitors were used for resonant circuits. Mica dielectric capacitors were invented in 1909 by William Dubilier. Prior to World War II, mica was the most common dielectric for capacitors in the United States.
Film capacitor
Polyimide (PI), a thermoplastic polymer of imide monomers, is proposed for film capacitors called Polyimide-, PI- or Kapton capacitors. Kapton is the trade name of polyimide from DuPont. This material is of interest because its high temperature resistance up to 400 °C. But as of 2012, no specific PI capacitor series film capacitors have been announced. The offered film capacitor, Kapton CapacitorCL11, announced from “dhgate” is a “Type: Polypropylene Film Capacitor”. Another very strange Kapton capacitor can be found at YEC, a Chinese producer of capacitors. Here the announced “Kapton capacitors” are in reality supercapacitors, a completely different technology Perhaps the Kapton film in these supercapacitors is used as a separator between the electrodes of this double-layer capacitor. Kapton films are often offered as an adhesive film for the outer insulation of capacitor packages.
History of AC power plugs and sockets
Several early American electrical plug and socket arrangements were invented by Harvey Hubbell. On 26 February 1903 he filed two patent applications featuring 2-pin plugs and adaptors for using his plugs with existing designs of lamp sockets and wall receptacles. Hubbell's first plug design had two round pins which differed from those already in use in Europe in that the tips of the pins had annular detents similar to those of present-day jack plugs to positively retain a plug in its socket. In one patent, US 774,250 a plug was used with a socket which screwed into a lampholder (like the early lampholder plugs). In the other patent US 776,326 the same type of plug was used with various three-way adaptors that could be connected to lampholders or "a receptacle of any ordinary type". Figures 2 and 4 of this patent show an adaptor plugged into what appears to be a "Chapman" receptacle.
Electricity
The capacitor is a development of the Leyden jar and is a device that can store charge, and thereby storing electrical energy in the resulting field. It consists of two conducting plates separated by a thin insulating dielectric layer; in practice, thin metal foils are coiled together, increasing the surface area per unit volume and therefore the capacitance. The unit of capacitance is the farad, named after Michael Faraday, and given the symbol "F": one farad is the capacitance that develops a potential difference of one volt when it stores a charge of one coulomb. A capacitor connected to a voltage supply initially causes a current as it accumulates charge; this current will however decay in time as the capacitor fills, eventually falling to zero. A capacitor will therefore not permit a steady state current, but instead blocks it.
Niobium capacitor
The phenomenon that can electrochemically form an oxide layer on aluminum and metals like tantalum or niobium, blocking an electric current in one direction but allowing it to flow in the other direction, was discovered in 1875 by the French researcher Eugène Ducretet. He coined the term "valve metal“ for such metals. Charles Pollak (born Karol Pollak) used this phenomenon for an idea of an polarized “Electric liquid capacitor with aluminum electrodes”. In 1896 Pollak obtained a patent for the first electrolytic capacitor. 
The first tantalum electrolytic capacitors with wound tantalum foils and non-solid electrolyte were developed in 1930 by Tansitor Electronics Inc., USA, and used for military purposes.
Ian A. Young
Young obtained his PhD from University of California, Berkeley in 1978, working with David A. Hodges, developing the first switched MOS capacitor circuits which later developed into analogue MOS switched capacitor filters.
Supercharger
On March 24, 1878 Heinrich Krigar of Germany obtained patent #4121, patenting the first ever screw-type compressor. Later that same year on August 16 he obtained patent #7116 after modifying and improving his original designs. His designs show a two-lobe rotor assembly with each rotor having the same shape as the other. Although the design resembled the Roots style compressor, the "screws" were clearly shown with 180 degrees of twist along their length. Unfortunately, the technology of the time was not sufficient to produce such a unit, and Heinrich made no further progress with the screw compressor. Nearly half a century later, in 1935, Alf Lysholm, who was working for Ljungströms Ångturbin AB (later known as Svenska Rotor Maskiner AB or SRM in 1951), patented a design with five female and four male rotors. He also patented the method for machining the compressor rotors.