The breakdown voltage of an insulator is the minimum voltage that causes a portion of an insulator to become electrically conductive. For diodes, the breakdown voltage is the minimum reverse voltage that makes the diode conduct appreciably in reverse; some devices have a forward breakdown voltage. Breakdown voltage is a characteristic of an insulator that defines the maximum voltage difference that can be applied across the material before the insulator conducts. In solid insulating materials, this creates a weakened path within the material by creating permanent molecular or physical changes by the sudden current. Within rarefied gases found in certain types of lamps, breakdown voltage is sometimes called the striking voltage; the breakdown voltage of a material is not a definite value because it is a form of failure and there is a statistical probability whether the material will fail at a given voltage. When a value is given it is the mean breakdown voltage of a large sample. Another term is withstand voltage, where the probability of failure at a given voltage is so low it is considered, when designing insulation, that the material will not fail at this voltage.
Two different breakdown voltage measurements of a material are the AC and impulse breakdown voltages. The AC voltage is the line frequency of the mains; the impulse breakdown voltage is simulating lightning strikes, uses a 1.2 microsecond rise for the wave to reach 90% amplitude drops back down to 50% amplitude after 50 microseconds. Two technical standards governing performing these tests are ASTM D1816 and ASTM D3300 published by ASTM. In standard conditions at atmospheric pressure, air serves as an excellent insulator, requiring the application of a significant voltage of 3.0 kV/mm before breaking down. In partial vacuum, this breakdown potential may decrease to an extent that two uninsulated surfaces with different potentials might induce the electrical breakdown of the surrounding gas; this may damage an apparatus. In a gas, the breakdown voltage can be determined by Paschen's law; the breakdown voltage in a partial vacuum is represented as V b = B p d ln − ln where V b is the breakdown potential in volts DC, A and B are constants that depend on the surrounding gas, p represents the pressure of the surrounding gas, d represents the distance in centimetres between the electrodes, γ s e represents the Secondary Electron Emission Coefficient.
A detailed derivation and some background information is given in the article about Paschen's law. Breakdown voltage is a parameter of a diode that defines the largest reverse voltage that can be applied without causing an exponential increase in the leakage current in the diode. Exceeding the breakdown voltage of a diode, per se, is not destructive. In fact, Zener diodes are just doped normal diodes that exploit the breakdown voltage of a diode to provide regulation of voltage levels. Rectifier diodes may have several voltage ratings, such as the peak inverse voltage across the diode, the maximum RMS input voltage to the rectifier circuit. Many small-signal transistors need to have any breakdown currents limited to much lower values to avoid excessive heating. To avoid damage to the device, to limit the effects excessive leakage current may have on the surrounding circuit, the following bipolar transistor maximum ratings are specified: VCEO (sometimes written BVCEO or VCEO The maximum voltage between collector and emitter that can be safely applied when no circuit at the base of the transistor is there to remove collector-base leakage.
Typical values: 20 volts to as high as 700 volts. VCBO The maximum collector-to-base voltage, with emitter open-circuit. Typical values 25 to 1200 volts. VCER The maximum voltage rating between collector and emitter with some specified resistance between base and emitter. A more realistic rating for real-world circuits than the open-base or open-emitter scenarios above. VEBO The maximum reverse voltage on the base with respect to the emitter. VCES Collector to emitter rating; some devices may have a maximum rate of change of voltage specified. Power transformers, circuit breakers and other electrical apparatus connected to overhead transmission lines are exposed to transi
E series of preferred numbers
The E series is a system of preferred numbers derived for use in electronic components. It consists of the E1, E3, E6, E12, E24, E48, E96 and E192 series, where the number after the'E' designates the quantity of value "steps" in each series. Although it is theoretically possible to produce components of any value, in practice the need for inventory simplification has led the industry to settle on the E series for resistors, capacitors and zener diodes. Other types of electrical components are either specified by the Renard series or are defined in relevant product standards. In the early 20th century and resistor value increments were different than today. World War II military production was a major influence for establishing common standards across many industries; the post–World War II baby boom and the invention of the transistor kicked off demand for consumer electronics goods during the 1950s. As transistor radio production migrated towards Japan during the 1950s, it was critical for the electronic industry to have international standards.
Over time, components evolved towards common values based on some of these existing conventions, the International Electrotechnical Commission began work on an international standard in 1948. The first version of this IEC Publication 63 was released in 1952. IEC 63 was revised and renamed into the current version known as IEC 60063:2015. IEC 60063 release history: IEC 63:1952, first edition, published 1952-01-01 IEC 63:1963, second edition, published 1963-01-01 IEC 63:1967/AMD1:1967, first amendment of second edition, published 1967 IEC 63:1977/AMD2:1977, second amendment of second edition, published 1977 IEC 60063:2015, third edition, published 2015-03-27 The E series of preferred numbers were chosen such that when a component is manufactured that it will end up in a range of equally spaced values on a logarithmic scale; each E series subdivides the interval from 1 to 10 into steps of 3, 6, 12, 24, 48, 96, 192. Subdivisions of E3 to E192 ensure the maximum error will be divided in the order of 40%, 20%, 10%, 5%, 2%, 1%, 0.5%.
The E192 series is used for 0.25% and 0.1% tolerance resistors. The E series is split into two major groupings: up to E24 is one group, E48 and higher is the other group; the two main differences between each major group is the number of significant digits and different rounding rules. Since lower E series up to E24 were defined and established long before the IEC standards were written, older series were not redefined when E48 to E192 series were created, otherwise it would have created problems in production and servicing of established products, it should be noted that some values in the E24 series don't exist in E48 to E192 series, due to the different rounding rules. The E3 series is defined as a series of the numbers 1.0, 2.2 and 4.7. If a manufacturer sold resistors with E3 series values in a range of 1 ohm to 10 megohms the available resistance values would be: 1 Ω, 2.2 Ω, 4.7 Ω, 10 Ω, 22 Ω, 47 Ω, 100 Ω, 220 Ω, 470 Ω, 1 kΩ, 2.2 kΩ, 4.7 kΩ, 10 kΩ, 22 kΩ, 47 kΩ, 100 kΩ, 220 kΩ, 470 kΩ, 1 MΩ, 2.2 MΩ, 4.7 MΩ, 10 MΩ.
The E1 series exists for historical reasons. The E3 series is used, except for some components with high variations like electrolytic capacitors, where the given tolerance is unbalanced between negative and positive such as −30/+50% or −20/+80%, or for components with uncritical values such as pull-up resistors; the calculated tolerance for this series gives ÷ = 36.60%. While the standard only specifies a tolerance greater than 20%, other sources indicate 40% or 50%. Most electrolytic capacitors are manufactured with values in the E6 or E12 series, thus E3 series is obsolete. Since some values in the E24 series do not exist in the E48, E96 and E192 series, resistor manufacturers have added the missing E24 values to some of their 1%, 0.5%, 0.25%, 0.1% tolerance families. This allows easier purchasing migration between different tolerance parts; this type of combination is noted on resistor datasheets and webpages as "E96 + E24" and "E192 + E24". Comparison of E24 vs. E48 values: matching – 1.00, 1.10, 7.50 missing – 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10Comparison of E24 vs. E96 values: matching – 1.00, 1.10, 1.30, 1.50, 2.00, 7.50 missing – 1.20, 1.60, 1.80, 2.20, 2.40, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 4.70, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10.
Comparison of E24 vs. E192 values: matching – 1.00, 1.10, 1.20, 1.30, 1.50, 1.60, 1.80, 2.00, 2.40, 4.70, 7.50 missing – 2.20, 2.70, 3.00, 3.30, 3.60, 3.90, 4.30, 5.10, 5.60, 6.20, 6.80, 8.20, 9.10 List of values for each E series: E1 value 1.0E3 values 1.0, 2.2, 4.7E6 values 1.0, 1.5, 2.2, 3.3, 4.7, 6.8E12 values 1.0, 1.2, 1.5, 1.8, 2.2, 2.7, 3.3, 3.9, 4.7, 5.6, 6.8, 8.2E24 values 1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1E48 values – 1.00, 1.05, 1.10, 1.15, 1.21, 1.27, 1.33, 1.40, 1.47, 1.54, 1.62, 1.69, 1.78, 1.87, 1.96, 2.05, 2.15, 2.26, 2.37, 2.49, 2.61, 2.74, 2.87, 3.01, 3.16, 3.32, 3.48, 3.65, 3.83, 4.02, 4.22, 4.42, 4.64, 4.87, 5.11, 5.36, 5.62, 5.90, 6.19, 6.49, 6.81, 7.15, 7.50, 7.87, 8.25, 8.66, 9.09, 9.53E96 values – 1.00, 1.02, 1.05, 1.07, 1.10, 1.13, 1.15, 1.18, 1.21, 1.24, 1.27, 1.30, 1.33, 1.37, 1.40, 1
A surge protector is an appliance or device designed to protect electrical devices from voltage spikes. A voltage spike is a transient event lasting 1 to 30 microseconds, that may reach over 1,000 volts. Lightning that hits a power line can give many thousands, sometimes 100,000 or more volts. A motor when switched off can generate a spike of 1,000 or more volts. Spikes can degrade wiring insulation and destroy electronic devices like battery chargers, modems and TVs. Spikes can occur on telephone and data lines when AC main lines accidentally connect to them or lightning hits them or the telephone and data lines travel near lines with a spike and the voltage is induced. A long term surge, lasting seconds, minutes, or hours, caused by power transformer failures such as a lost neutral or other power company error, are not protected by transient protectors. Long term surges can destroy the protectors in area. Tens of milliseconds can be longer than a protector can handle. Long term surges may not be handled by fuses and over voltage relays.
A transient surge protector attempts to limit the voltage supplied to an electric device by either blocking or shorting current to reduce the voltage below a safe threshold. Blocking is done by using inductors. Shorting is done by spark gaps, discharge tubes, zener-type semiconductors, MOVs, all of which begin to conduct current once a certain voltage threshold is reached, or by capacitors which inhibit a sudden change in voltage; some surge protectors use multiple elements. The most common and effective way is the shorting method in which the electrical lines are temporarily shorted together until the voltage is reduced by the resistance in the power lines; the spike's energy is dissipated in the power lines, converted to heat. Since a spike lasts only 10s of microseconds, the temperature rise is minimal. However, if the spike is large enough, like a nearby hit by lightning, there might not be enough power line or ground resistance and the MOV can be destroyed and power lines melted. Surge protectors for homes can be in power strips used inside, or a device outside at the power panel.
A modern house has three wires, Line and Ground. Many protectors will connect to all three, in pairs, L-N,L-G,and N-G, since there are conditions, like lightning, where both L and N have high voltage spikes that need to be shorted to ground; the terms surge protection device and transient voltage surge suppressor are used to describe electrical devices installed in power distribution panels, process control systems, communications systems, other heavy-duty industrial systems, for the purpose of protecting against electrical surges and spikes, including those caused by lightning. Scaled-down versions of these devices are sometimes installed in residential service entrance electrical panels, to protect equipment in a household from similar hazards. Many power strips have basic surge protection built in. However, in unregulated countries there are power strips labelled as "surge" or "spike" protectors that only have a capacitor or RFI circuit that do not provide true spike protection; these are some of the most prominently featured specifications which define a surge protector for AC mains, as well as for some data communications protection applications.
Known as the let-through voltage, this specifies what spike voltage will cause the protective components inside a surge protector to short or clamp. A lower clamping voltage indicates better protection, but can sometimes result in a shorter life expectancy for the overall protective system; the lowest three levels of protection defined in the UL rating are 330 V, 400 V and 500 V. The standard let-through voltage for 120 V AC devices is 330 volts. Underwriters Laboratories, a global independent safety science company, defines how a protector may be used safely. UL 1449 became compliance mandatory with the 3rd edition in September 2009 to increase safety compared to products conforming to the 2nd edition. A measured limiting voltage test, using six times higher current, defines a voltage protection rating. For a specific protector, this voltage may be higher compared to a Suppressed Voltage Ratings in previous editions that measured let-through voltage with less current. Due to non-linear characteristics of protectors, let-through voltages defined by 2nd edition and 3rd edition testing are not comparable.
A protector may be larger to obtain a same let-through voltage during 3rd edition testing. Therefore, a 3rd edition or protector should provide superior safety with increased life expectancy. A protector with a higher let-through voltage, e.g.400v vs 330v, will pass a higher voltage to the connected device. The design of the connected device determines. Motors and mechanical devices are not affected; some electronic parts, like chargers, LED or CFL bulbs and computerized appliances are sensitive and can be compromised and have their life reduced. The Joule rating number defines how much energy a MOV-based surge protector can theoretically absorb in a single event, without failure. Better protectors exceed ratings of 40,000 amperes. Since the actual duration of a spike is only about 10 microseconds, the actual power dissipated in the MOV is only 1 to 20 watts. Any more than that and the MOV will fuse, or sometimes short and melt blowing a fuse, disconnecting itself from the circuit; the MOV (or
Passivity is a property of engineering systems, used in a variety of engineering disciplines, but most found in analog electronics and control systems. A passive component, depending on field, may be either a component that consumes but does not produce energy or a component, incapable of power gain. A component, not passive is called an active component. An electronic circuit consisting of passive components is called a passive circuit and has the same properties as a passive component. Used out-of-context and without a qualifier, the term passive is ambiguous. Analog designers use this term to refer to incrementally passive components and systems, while control systems engineers will use this to refer to thermodynamically passive ones. Systems for which the small signal model is not passive are sometimes called locally active. Systems that can generate power about a time-variant unperturbed state are called parametrically active. In control systems and circuit network theory, a passive component or circuit is one that consumes energy, but does not produce energy.
Under this methodology and current sources are considered active, while resistors, inductors, tunnel diodes and other dissipative and energy-neutral components are considered passive. Circuit designers will sometimes refer to this class of components as dissipative, or thermodynamically passive. While many books give definitions for passivity, many of these contain subtle errors in how initial conditions are treated and the definitions do not generalize to all types of nonlinear time-varying systems with memory. Below is a correct, formal definition, taken from Wyatt et al. which explains the problems with many other definitions. Given an n-port R with a state representation S, initial state x, define available energy EA as: E A = sup x → T ≥ 0 ∫ 0 T − ⟨ v, i ⟩ d t where the notation supx→T≥0 indicates that the supremum is taken over all T ≥ 0 and all admissible pairs with the fixed initial state x. A system is considered passive if EA is finite for all initial states x. Otherwise, the system is considered active.
Speaking, the inner product ⟨ v, i ⟩ is the instantaneous power, EA is the upper bound on the integral of the instantaneous power. This upper bound is the available energy in the system for the particular initial condition x. If, for all possible initial states of the system, the energy available is finite the system is called passive. In circuit design, passive components refer to ones that are not capable of power gain. Under this definition, passive components include capacitors, resistors, transformers, voltage sources, current sources, they exclude devices like transistors, vacuum tubes, tunnel diodes, glow tubes. Formally, for a memoryless two-terminal element, this means that the current–voltage characteristic is monotonically increasing. For this reason, control systems and circuit network theorists refer to these devices as locally passive, incrementally passive, monotone increasing, or monotonic, it is not clear how this definition would be formalized to multiport devices with memory – as a practical matter, circuit designers use this term informally, so it may not be necessary to formalize it.
This term is used colloquially in a number of other contexts: A passive USB to PS/2 adapter consists of wires, resistors and similar passive components. An active USB to PS/2 adapter consists of logic to translate signals A passive mixer consists of just resistors, whereas an active mixer includes components capable of gain. In audio work one can find both passive and active converters between balanced and unbalanced lines. A passive bal/unbal converter is just a transformer along with, of course, the requisite connectors, while an active one consists of a differential drive or an instrumentation amplifier. In some informal settings, passivity may refer to the simplicity of the device, although this definition is now universally considered incorrect. Here, devices like diodes would be considered active, only simple devices like capacitors and resistors are considered passive. In some cases, the term "linear element" may be a more appropriate term than "passive device." In other cases, "solid state device" may be a more appropriate term than "active device."
Passivity, in most cases, can be used to demonstrate that passive circuits will be stable under specific criteria. Note that this only works if only one of the above definitions of passivity is used – if components from the two are mixed, the systems may be unstable under any criteria. In addition, passive circuits will not be stable under all stabilit
Quantum tunnelling or tunneling is the quantum mechanical phenomenon where a subatomic particle passes through a potential barrier that it cannot surmount under the provision of classical mechanics. Quantum tunnelling plays an essential role in several physical phenomena, such as the nuclear fusion that occurs in main sequence stars like the Sun, it has important applications in the tunnel diode, quantum computing, in the scanning tunnelling microscope. The effect was predicted in the early 20th century, its acceptance as a general physical phenomenon came mid-century. Fundamental quantum mechanical concepts are central to this phenomenon, which makes quantum tunnelling one of the novel implications of quantum mechanics. Quantum tunneling is projected to create physical limits to the size of the transistors used in microprocessors, due to electrons being able to tunnel past them if the transistors are too small. Tunnelling is explained in terms of the Heisenberg uncertainty principle that the quantum object can be known as a wave or as a particle in general.
Quantum tunnelling was developed from the study of radioactivity, discovered in 1896 by Henri Becquerel. Radioactivity was examined further by Marie Curie and Pierre Curie, for which they earned the Nobel Prize in Physics in 1903. Ernest Rutherford and Egon Schweidler studied its nature, verified empirically by Friedrich Kohlrausch; the idea of the half-life and the possibility of predicting decay was created from their work. In 1901, Robert Francis Earhart, while investigating the conduction of gases between spaced electrodes using the Michelson interferometer to measure the spacing, discovered an unexpected conduction regime. J. J. Thomson commented. In 1911 and 1914, then-graduate student Franz Rother, employing Earhart's method for controlling and measuring the electrode separation but with a sensitive platform galvanometer, directly measured steady field emission currents. In 1926, using a still newer platform galvanometer of sensitivity 26 pA, measured the field emission currents in a "hard" vacuum between spaced electrodes.
Quantum tunneling was first noticed in 1927 by Friedrich Hund when he was calculating the ground state of the double-well potential and independently in the same year by Leonid Mandelstam and Mikhail Leontovich in their analysis of the implications of the new Schrödinger wave equation for the motion of a particle in a confining potential of a limited spatial extent. Its first application was a mathematical explanation for alpha decay, done in 1928 by George Gamow and independently by Ronald Gurney and Edward Condon; the two researchers solved the Schrödinger equation for a model nuclear potential and derived a relationship between the half-life of the particle and the energy of emission that depended directly on the mathematical probability of tunnelling. After attending a seminar by Gamow, Max Born recognised the generality of tunnelling, he realised that it was not restricted to nuclear physics, but was a general result of quantum mechanics that applies to many different systems. Shortly thereafter, both groups considered the case of particles tunnelling into the nucleus.
The study of semiconductors and the development of transistors and diodes led to the acceptance of electron tunnelling in solids by 1957. The work of Leo Esaki, Ivar Giaever and Brian Josephson predicted the tunnelling of superconducting Cooper pairs, for which they received the Nobel Prize in Physics in 1973. In 2016, the quantum tunneling of water was discovered. Quantum tunnelling falls under the domain of quantum mechanics: the study of what happens at the quantum scale; this process cannot be directly perceived, but much of its understanding is shaped by the microscopic world, which classical mechanics cannot adequately explain. To understand the phenomenon, particles attempting to travel between potential barriers can be compared to a ball trying to roll over a hill. Classical mechanics predicts that particles that do not have enough energy to classically surmount a barrier will not be able to reach the other side. Thus, a ball without sufficient energy to surmount the hill would roll back down.
Or, lacking the energy to penetrate a wall, it would bounce back or in the extreme case, bury itself inside the wall. In quantum mechanics, these particles can, with a small probability, tunnel to the other side, thus crossing the barrier. Here, the "ball" could, in a sense, borrow energy from its surroundings to tunnel through the wall or "roll over the hill", paying it back by making the reflected electrons more energetic than they otherwise would have been; the reason for this difference comes from the treatment of matter in quantum mechanics as having properties of waves and particles. One interpretation of this duality involves the Heisenberg uncertainty principle, which defines a limit on how the position and the momentum of a particle can be known at the same time; this implies that there are no solutions with a probability of zero, though a solution may approach infinity if, for example, the calculation for its position was taken as a probability of 1, the other, i.e. its speed, would have to be infinity.
Hence, the probability of a given particle's existence on the opposite side of an intervening barrier is non-zero, such particles will appear on the'other' side with a relative frequency proportional to this probability. The wave function of a particle summarises everything that can be known about a physical s
Electrostatic discharge is the sudden flow of electricity between two electrically charged objects caused by contact, an electrical short, or dielectric breakdown. A buildup of static electricity can be caused by electrostatic induction; the ESD occurs when differently-charged objects are brought close together or when the dielectric between them breaks down creating a visible spark. ESD can create spectacular electric sparks, but less dramatic forms which may be neither seen nor heard, yet still be large enough to cause damage to sensitive electronic devices. Electric sparks require a field strength above 40 kV/cm in air, as notably occurs in lightning strikes. Other forms of ESD include corona discharge from sharp electrodes and brush discharge from blunt electrodes. ESD can cause harmful effects of importance in industry, including explosions in gas, fuel vapor and coal dust, as well as failure of solid state electronics components such as integrated circuits; these can suffer permanent damage.
Electronics manufacturers therefore establish electrostatic protective areas free of static, using measures to prevent charging, such as avoiding charging materials and measures to remove static such as grounding human workers, providing antistatic devices, controlling humidity. ESD simulators may be used to test electronic devices, for example with a human body model or a charged device model. One of the causes of ESD events is static electricity. Static electricity is generated through tribocharging, the separation of electric charges that occurs when two materials are brought into contact and separated. Examples of tribocharging include walking on a rug, rubbing a plastic comb against dry hair, rubbing a balloon against a sweater, ascending from a fabric car seat, or removing some types of plastic packaging. In all these cases, the breaking of contact between two materials results in tribocharging, thus creating a difference of electrical potential that can lead to an ESD event. Another cause of ESD damage is through electrostatic induction.
This occurs when an electrically charged object is placed near a conductive object isolated from the ground. The presence of the charged object creates an electrostatic field that causes electrical charges on the surface of the other object to redistribute. Though the net electrostatic charge of the object has not changed, it now has regions of excess positive and negative charges. An ESD event may occur. For example, charged regions on the surfaces of styrofoam cups or bags can induce potential on nearby ESD sensitive components via electrostatic induction and an ESD event may occur if the component is touched with a metallic tool. ESD can be caused by energetic charged particles impinging on an object; this causes deep charging. This is a known hazard for most spacecraft; the most spectacular form of ESD is the spark, which occurs when a heavy electric field creates an ionized conductive channel in air. This can cause minor discomfort to people, severe damage to electronic equipment, fires and explosions if the air contains combustible gases or particles.
However, many ESD events occur without a audible spark. A person carrying a small electric charge may not feel a discharge, sufficient to damage sensitive electronic components; some devices may be damaged by discharges as small as 30 V. These invisible forms of ESD can cause outright device failures, or less obvious forms of degradation that may affect the long term reliability and performance of electronic devices; the degradation in some devices may not become evident until well into their service life. A spark is triggered when the electric field strength exceeds 4–30 kV/cm — the dielectric field strength of air; this may cause a rapid increase in the number of free electrons and ions in the air, temporarily causing the air to abruptly become an electrical conductor in a process called dielectric breakdown. The best known example of a natural spark is lightning. In this case the electric potential between a cloud and ground, or between two clouds, is hundreds of millions of volts; the resulting current.
On a much smaller scale, sparks can form in air during electrostatic discharges from charged objects that are charged to as little as 380 V. Earth's atmosphere consists of 78 % nitrogen. During an electrostatic discharge, such as a lightning flash, the affected atmospheric molecules become electrically overstressed; the diatomic oxygen molecules are split, recombine to form ozone, unstable, or reacts with metals and organic matter. If the electrical stress is high enough, nitrogen oxides can form. Both products are toxic to animals, nitrogen oxides are essential for nitrogen fixation. Ozone is used in water purification. Sparks are an ignition source in combustible environments that may lead to catastrophic explosions in concentrated fuel environments. Most explosions can be traced back to a tiny electrostatic discharge, whether it was an unexpected combustible fuel leak invading a known open air sparking device, or an unexpected spark in a known fuel rich environment; the end result is the same if oxygen is present and the three criteria of the fire triangle have been combined.
Many electronic components microchips, can be damaged by ESD. Sensitive components need to be protected during and after manufacture, during shipping and device assembly
Clarence Melvin Zener was the American physicist who first described the property concerning the breakdown of electrical insulators. These findings were exploited by Bell Labs in the development of the Zener diode, duly named after him. Zener was a theoretical physicist with a background in mathematics who conducted research in a wide range of subjects including: superconductivity, ferromagnetism, fracture mechanics and geometric programming. Zener was born in Indianapolis and earned his PhD in physics under Edwin Kemble at Harvard in 1929, his thesis was entitled Quantum Mechanics of the Formation of Certain Types of Diatomic Molecules. In 1957 he received the Bingham Medal for his work in rheology, in 1959 received the John Price Wetherill Medal from The Franklin Institute and in 1985 received the ICIFUAS Prize for his seminal work on anelasticity of metals. A notable doctoral student of Zener's was John B. Goodenough and Arthur S. Nowick held a postdoctoral appointment under Zener. Zener was known both for his dislike of experimental work and for preferring to work on practical problems within the arena of applied physics, in which he was insightful.
Although he had a reputation of being successful in these endeavors, he considered himself as being less qualified to work on purely theoretical physics problems. In recognition of this, he once commented that after dining with physicist J. Robert Oppenheimer: "when it came to fundamental physics, it was clear there was no point in competing with a person like that." Zener held the following posts/appointments: He was a research fellow at the University of Bristol from 1932 to 1934. He taught at Washington University in St. Louis, the City College of New York, Washington State University before working at the Watertown Arsenal during World War II. After the war, he taught at University of Chicago where he was Professor of Physics, before being appointed as Director of Science at Pittsburgh's Westinghouse. Here he developed his system of Geometric programming, which he used to solve engineering problems using adjustable parameters, defined by mathematical functions. Using this, Zener modelled designs for heat exchangers, to perform ocean thermal energy conversion, discovered the most suitable areas for their deployment.
Following his career at Westinghouse, Zener returned to teaching, leaving Pittsburgh to become a professor at Texas A&M University but returned to finish his career at Carnegie Mellon University. Zener effect Zener diode Zener pinning Zener–Hollomon parameter Landau–Zener formula Zener double-exchange mechanism Zener ratio, an elastic anisotropy factor for cubic crystals Zener Prize National Academy of Sciences Biography Clarence Zener at Find a Grave