History of electricity

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Acceptor impurities: Doping impurities used in semiconductor manufacturing causing weakly bound electrons to be stripped from the crystalline lattice structure. Acceptor impurities are used to produce P-type semiconductor material.

Amp hour: A battery’s rating given supplied amperage and a time period. A battery with a rating of one amp-hour will deliver one amp of current for one hour.

Barrier region: The junction in semiconductors where P-type and N-type materials converge. Depending on the biasing, the barrier region will allow or disallow current flow, also known as the depletion region.

Base current: Current that flows through the base of a bi-polar transistor.

Battery: A device that provides stable, predictable power for electronic and electrical devices.

Bias: The process of applying potentials to the various parts of semiconductors.

Breakdown: The point at which a reverse biased semiconductor will begin to conduct opposite its intended direction. Although some semiconductors are designed to operate in this way, this will typically result in the destruction of the component.

Capacitance: The capability of a body, system, circuit, or device for storing electric charge. Capacitance is expressed as the ratio of stored charge in coulombs to the impressed potential difference in volts. The resulting unit of capacitance is the farad.

Capacitor: An electronic component used for storing an electrical charge.

Charge carriers: In electronics, the constituent carriers for positive and negative electrical charges. Electrons are the negative carriers, and holes, or the absence of electrons in the orbit of an atom, are the positive charge carriers.

Charges: The fundamental property of subatomic particles that determines their electromagnetic interactions. Matter that possesses a charge is influenced by and produces electromagnetic fields. The interaction between charge and an electromagnetic field is the source of one of the four fundamental forces, the electromagnetic force.

Collector current: The bulk of current flow through a bi-polar transistor, from emitter to collector in the case of an NPN and from collector to emitter in the case of a PNP.

Common: In electricity and electronics the most negative point in a circuit, often referred to as ground or negative.

Conductors: Substances that possess chemical properties that make them suitable to allow unrestricted current flow.

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Crystalline lattice: A unique arrangement of atoms in a crystal. A crystal structure comprises a unit cell and a set of atoms arranged in a particular way and periodically repeated in three dimensions on a lattice. The spacing among unit cells in various directions is called its lattice parameters. The symmetry properties of the crystal are embodied in its space group. A crystal’s structure and symmetry play a role in determining many of its properties, such as cleavage, electronic band structure, and optical properties.

Depletion region: The junction in semiconductors where P-type and N-type materials converge. Depending on the biasing, the depletion region will allow or disallow current flow. Also known as the barrier region.

Dielectric: A substance that is highly resistant to flow of electric current. Layers of such substances are commonly inserted into capacitors to improve their performance.

Donor impurities: Doping impurities used in semiconductor manufacturing causing an excess number of loosely bound electrons in the crystalline lattice structure of the molecule. Donor impurities are used to produce N-type semiconductor material.

Electromagnetism: The physics of the electromagnetic field, including its effect on electrically charged particles. Almost all of the phenomena one encounters in daily life (with the exception of gravity) result from electromagnetism. The forces between atoms, including the attractive forces between atoms in a solid that cause the rigidity of solids, are predominantly electromagnetic, from the positive electric charge of the protons in atomic nuclei and the negative electric charge of the electrons surrounding the nuclei. The forces acting on the electrons in atoms that cause the varied phenomena observed in chemical reactions are also predominantly electromagnetic. Light can be described as a set of traveling disturbances in the electromagnetic field (i.e., electromagnetic waves), so all optical phenomena are actually electromagnetic in nature.

Electromotive force: The force, measured in volts, that is produced by interaction between a current and a magnetic field, at least one of which is changing.

Forward Biased: The application of voltage potentials to the constituent parts of a semiconductor that produce conditions that allow current to flow.

Ganged: Connected together and operated by a single mechanical device, as in a switch.

Holes: In electricity, the absence of an orbital electron in the atom of a conductor — the positive charge carrier.

Impurity doping: The process of adding certain chemicals to intrinsic semiconductor material imparting either an absence or excess number of electrons.

Insulators: Substances that have very tightly bound orbital electrons and do not possess properties that allow electrical current to flow.

Negative ion: An atom with more orbital electrons that nuclear protons.

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Non-polarized: In electronics, a component in which current will flow in either direction regardless of polarity.

Normally closed: A switch or set of switch contacts that allows current to flow.

Normally open: A switch or set of switch contacts that, when in a static state, allows no current to flow.

N-type materials: Semiconductor materials that have been “doped” with donor impurities, causing an excess number of electrons.

Ohm: A unit of electrical resistance, defined as the resistance in a circuit in which a potential difference of one volt creates a current of one ampere.

Photo electric cells: Devices whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is upon it. The most common type consists of two electrodes separated by a light- sensitive semiconductor material.

Photoelectric effect: Emission of electrons by substances, especially metals, when light falls on their surfaces.

Photo-resistor: A resistor whose resistance is indirectly proportional to the amount of light upon it.

PN junction: In semiconductors, the minute region surrounding the area where P-type and N-type materials intersect. The PN junction is the basis for all solid state components.

Polarity: The intrinsic separation, alignment, or orientation of two bodies with respect to the electromagnetic charges.

Positive ion: An atom with less orbital electrons than nuclear protons.

Potential: In electricity, the work required to move a unit of positive charge to a designated point in a static electric field.

Potentiometer: A variable resistor.

P-type material: Semiconductor materials that have been “doped” with acceptor impurities, causing holes, or absence of electrons.

Resistance: The opposition of a body or substance to current passing through it, resulting in a change of electrical energy into heat or another form of energy.

Reversed biased: The application of voltage potentials to the constituent parts of a semiconductor that produce conditions that disallow current flow.

Rheostat: A continuously variable electrical resistor used to regulate current.

Series: A circuit with only a single path for current to flow.

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Series/parallel: A circuit that contains both properties of series and parallel circuits.

Short circuit: A circuit containing no resistance, typically dangerous and results in very high values of current.

Strong nuclear force: That force that binds the nuclear particles of an atom together.

Voltage: A potential or difference in potential that induces current flow in conductors.

Voltage drop: A decrease in voltage in a circuit caused by resistance.

Weak nuclear force: That force that binds electrons to orbit around the nucleus of atoms.

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