1. The electromotive force, potential, or potential difference, measured in volts, which causes current to flow in an electric circuit>
2. The potential difference between two electrodes, as measured in volts.
3. The rate at which energy is drawn from a source that produces a flow of electricity in a circuit; expressed in volts.

Voltage is often compared to water pressure or are often given relative to "earth" or "ground" which is taken to be at zero volts. A circuit's earth may or may not be electrically connected to the actual earth.

4. A term sometimes used interchangeably with electrical potential.

The electrical potential difference between two points in a circuit is the cause of the flow of a current.

Voltage is measured in volts, millivolts, microvolts, and kilovolts and the terms electromotive force, potential, potential difference, and voltage drop are all often called voltage.

For an alternating voltage, the root-mean square voltage.

1. The potential developed by a metal or other electrode material immersed in an electrolytic solution; usually related to the standard potential of the hydrogen electrode, which is established at zero.
2. The instantaneous voltage of an electrode with respect to the cathode of an electron tube.
3. The voltage existing between an electrode and the solution or electrolyte in which it is immersed.

1. An instrument that maintains the direct-current power supply voltage for electronic equipment which is nearly constant in spite of the input alternating-current line voltage variations and output load variations.
2. A type of regulator that uses all solid state devices to perform the regulatory functions.

Electrophoresis, often using paper as a support to the solution, in which a high potential, often a few kilovolts, is used.

Electrophoresis is the motion of charged particles in a colloid (mixture in which one substance is divided into minute particles, called colloidal particles, and dispersed throughout a second substance) under the influence of an electric field. Particles with a positive charge go to the cathode and negative charge to the anode.

The half-cycle of alternating current in which there is no current or no minimal current flow through the electrical component or equipment.

The voltage, applied across the electrodes in the detecting chamber of a radiation detection instrument, that enables the detection of an ionizing event.

The maximal electric potential of a pulsating supply or of an alternating supply during the half-cycle in which flow of current occurs.

As electrical potential which is unidirectional but varies in magnitude at a periodic frequency.

The time-varying part of a voltage that is ideally time-invariant.

Most electronic systems require a direct-current voltage for at least part of their operation.

An ideal direct-current voltage is available from a battery, but batteries are impractical for many applications.

To obtain a direct-current voltage from the alternating-current power mains requires using some type of power supply.

The voltage regulator is usually an electronic circuit that is specifically designed to provide a very stable direct current output voltage even if large variations occur in the input.

Nonlinear power supplies, which are often termed switching power supplies or switched-mode power supplies, are becoming increasingly popular as a practical alternative for producing a low-ripple direct current output.

The minimum voltage at which a spark discharge occurs between electrodes of a given shape at a given distance away from each one and under certain conditions.

The voltage required for a radiation counter to function.

1. The minimum voltage that must be applied to an electronic device to produce a particular operating characteristic.
2. The minimal voltage at which all the pulses produced by an ionizing even are of the same size regardless of the magnitude of the event.

The increasing of an input-signal voltage to produce a higher output-signal voltage: "The ratio of the magnitude of the voltage amplification across a specified load impedance to the magnitude of the input voltage of the amplifier or other transducer feeding that load is often expressed in decibels by multiplying the common logarithm of the ratio by 20."

1. An electronic circuit whose function is to accept an input voltage and produce a magnified, accurate replica of this voltage as an output voltage.

The voltage gain of the amplifier is the amplitude ratio of the output voltage to the input voltage.

2. An amplifier designed primarily to build up the voltage of a signal or to increase a signal's voltage, without supplying appreciable power.

The ratio of the magnitude of the voltage across the input of a transducer to the magnitude of the voltage delivered to a specified load impedance connected to the transducer.

It is expressed in decibels by multiplying the common logarithm of the ratio by 20.

A voltage source that provides an adjustable high-accuracy calibration voltage for calibrating measuring instruments.

The electrode voltage that reduces the anode current, beam current, or some other electron-tube or transistor characteristic to a specified low value.

An effect in which the peak voltage of a battery drops more quickly than normal as it is used, even though the total power remains almost the same; often caused by repeated overcharging of the battery.

1. A unit of electric measurement equal to the product of a volt and an ampere that for direct current constitutes a measure of power equivalent to a watt.
2. A tapped resistor, adjustable resistor, potentiometer, or a series arrangement of two or more fixed resistors connected across a voltage source.

A desired fraction of the total voltage is obtained from the intermediate tap, movable contact, or resistor junction.

1. A rectifier circuit that gives approximately double the output voltage of a conventional half-wave vacuum-tube rectifier by charging a capacitor during the normally wasted half-cycle and discharging it in a series with the output voltage during the next half-cycle.
2. An electric circuit for rectifying alternating current in which two rectifiers give double the output voltage available using a single rectifier.

1. The voltage difference between any two specific points in a circuit.
2. The voltage developed across a component or conductor by the flow of current through the resistance or impedance of that component or conductor.
3. The decline in voltage in an electrical circuit because of the resistance in the conducting line.

This is why longer electrical runs in a building require thicker gauge wire and why AC power is transmitted over high-voltage lines.

Higher current requires thicker and more expensive wires, but higher voltage does not. The high-voltage lines are reduced by transformers near the end of the line.

Excitation of a transmitting antenna by applying voltage at a point of maximum potential; at a voltage loop or antinode.

1. A feedback configuration where a portion of the output voltage is fed back to the input of an amplifier.
2. Feedback in which the voltage drop across part of a load impedance acts in a series with the input signal voltage.

1. An amplifier used after an oscillator or other critical stage to isolate it from the effects of load impedance variations in subsequent stages. Also known as buffer; buffer stage.
2. An analog device that is typically used for impedance matching and signal isolation; for example, a sound card typically uses buffer amps at most of its input and output ports.
3. An operational amplifier that has no feedback components but has a direct feedback connection from the output to the inverting input to give unity gain so the output voltage follows the non-inverting input voltage.

A voltage follower has a very high input impedance and a very low output impedance.

The difference between the output signal voltage level in decibels and the input signal voltage level in decibels.

This value is equal to twenty times the common logarithm of the ratio of the output voltage to the input voltage.

The voltage gain is equal to the amplification factor of the tube or transistor only for a matched load.

A two-terminal circuit element in which the terminal voltage is independent of the current through the element or component.

1. The voltage per unit length along a resistor or other conductive path.
2. The electric field in a region, defined as the potential difference between two points divided by the distance between them.

An abrupt change or discontinuity in tube voltage drop during operation of a glow-discharge tube.

1. The law that at each instant of time the algebraic sum of the voltage rises around a closed loop in a network is equal to the algebraic sum of the voltage drops, both being taken in the same direction around the loop.
2. The statement that the sum of all currents flowing into a node is zero; conversely, the sum of all currents leaving a node must be zero.

Gustav Kirchhoff (184-1887) was a German physicist noted for his formulation of laws related to the conduction of electricity. He also made major contributions in the study of spectroscopy and advanced research into blackbody radiation (emission of radiant energy which would take place from a blackbody at a fixed temperature).

A blackbody is the theoretical surface that absorbs all radiant energy that falls on it, and radiates electromagnetic energy at all frequencies, from radio waves to gamma rays. Because all visible light falling on such a surface is absorbed without reflection, the surface will appear black as long as its temperature is such that its emission peak is not in the visible portion of the spectrum.

An antinode at which voltage is at a maximum.

1. A rectifier circuit capable of supplying a direct-current output voltage that is two or more times the peak value of the alternating-current voltage.
2. An electronic circuit that converts AC to DC and multiplies the source voltage.

It consists of capacitor/diode pairs, the capacitor stores the source voltage like a charge pump, and the diode rectifies it.

The output voltage is roughly the input voltage times the number of capacitor/diode pairs; for example, a voltage doubler uses two capacitor/diode pairs while a voltage tripler uses three pairs.

A point having zero voltage in a stationary wave system, as in an antenna or transmission line; for example, a voltage node exists at the center of a half-wave antenna.

The maximum sustained voltage that can safely be applied to an electric device without risking the possibility of electric breakdown.

1. The ratio of the complex electric field strength or voltage of a reflected wave to that of the incident wave.
2. The ratio of the phasor representing the magnitude and phase of the electric field of the backward-traveling wave at a specified cross section of a waveguide to the phasor representing the forward-traveling wave at the same cross section.

1. The ratio of the difference between no-load and full-load output voltage of a device to the full-load output voltage, expressed as a percentage.
2. The change in voltage magnitude that occurs when the load (at a specified power factor) is reduced from the rated or nominal value to zero, with no intentional manual readjustment of any voltage control, expressed in percent of nominal full-load voltage.

Voltage regulation is a convenient measure of the sensitivity of a device to changes in loading.

1. A circuit or device that produces a nearly constant voltage output, even when the voltage input (line) and current output (load) may vary considerably.
2. A device that maintains the terminal voltage of a generator or other voltage source within required limits despite variations in input voltage or load.
3. A circuit that includes a sensor capable of monitoring the load and restoring the output voltage to close tolerance limits despite changes in both the load and the input voltage.
4. Any electrical or electronic device that maintains the voltage of a power source within acceptable limits.

The voltage regulator is needed to keep voltages within the prescribed range that can be tolerated by the electrical equipment using that voltage.

Voltage regulators also are used in electronic equipment in which excessive variations in voltage would be detrimental.

A relay that functions at a predetermined value of voltage.

An excessive discharge of a battery that causes the cells with the least capacity to be partly recharged in the reverse direction which tends to result in cell damage.

1. In an electron tube, the valence of the anode current which does not further increase with an increase in anode voltage.

The term anode is a general term for the electrode, terminal, or element through which current enters a conductor; so called from the path the electrical current was thought to take.

2. A situation in which the anode current of an electron tube can not be further increased by increasing the anode voltage.

The electrons are then being drawn to the anode at the same rate as they are emitted from the cathode.

A voltage source whose value is known to s high degree of accuracy; for example a standard cell.

An electrically operated instrument that indicates voltage standing-wave ratios and is calibrated in voltage ratios.

1. A transformer in which the primary winding is connected in parallel with a circuit in which the voltage is to be measured or controlled.
2. A transformer utilized o transform voltage with little or no current.
3. A small step-up transformer used for increasing the sensitivity for an AC voltmeter.
4. An instrument transformer that has a primary winding connected in parallel with a circuit in which the voltage is to be measured or controlled.

A capacitor whose capacitance value can be changed by varying an externally applied bias voltage, as in a silicon capacitor.

A crystal oscillator circuit whose oscillator output frequency can be varied or swept over a range of frequencies by varying a DC modulating voltage.

1. An oscillator whose frequency of oscillation can be varied by changing an applied voltage.
2. An oscillator having an output frequency that varies with the applied direct current control voltage.
3. An electronic oscillator designed to be controlled in oscillation frequency by a voltage input.
3. An oscillator having an output frequency that varies with the applied direct current control voltage.

1. The replacement of elements of one circuit pair by their dual elements in another circuit, according to the duality principle.
2. A pair of circuits in which the elements of one circuit are replaced by their dual elements in the other circuit according to the duality principle; for example, currents are replaced by voltages, capacitances by resistances.

A two-electrode semiconductor device having a voltage-dependent nonlinear resistance.

Its resistance drops as the applied voltage is increased.

A description of a system that incorporates a mechanical identifier on batteries and devices to ensure that only batteries of the correct voltage are connected to the device.

A gas tube whose voltage drop is approximately constant over the operating range of current and is also relatively stable with time at fixed values of current and temperature.

A power supply that operates from an AC line and delivers a regulated AC output voltage, usually adjustable, at the same frequency or at some other frequency.

1. A power transformer that delivers an essentially constant output voltage over a wide range of input voltage values.
2. Saturated-core type of a transformer that holds output voltage to within a few percent (5% above or below normal) with input variations up to 20% above or below normal;.

Considerable harmonic distortion results unless extensive filters are utilized.

1. A diode in which the voltage is independent of the current for a considerable range of current values; such as, a Zener diode or a two-terminal semiconductor junction device with a very sharp voltage breakdown as a reverse bias is applied.

The diode may be used as the main component of a simple voltage regulator, or as a constant voltage reference for a more elaborate voltage regulator circuit.

2. A diode that maintains an essentially constant direct voltage in a circuit despite changes in line voltage or load.

1. A glow-discharge tube that maintains an essentially constant tube voltage drop over the operating range of current.
2. A glow-discharge tube in which the tube voltage drop is approximately constant over the operating range of current.

It is used to maintain an essentially constant direct voltage in a circuit despite changes in line voltage or load.

A resistor whose value varies with applied voltage over at least a part of its voltage range.

It might consist of one or more mineral crystals or two or more metallic oxide disks, but it does not have rectifying properties.

A gas-filled tube normally working with a glow discharge in that part of the characteristic where the voltage is practically independent of current.

The ratio of the amplitude of the electric field or voltage at a voltage minimum to that at an adjacent maximum in a stationary-wave system; as in a waveguide, coaxial cable, or other transmission line.

1. A device that converts an analogue input voltage into a sequence of digital pulses with a frequency that is proportional to the input voltage.
2. A converter that has an output frequency which is a function of some reference or control signal.

This digital output can be fed into a computer for a process control or for other applications.

An oscillator tube that has an operating frequency which can be varied by changing one or more of the electrode voltages; as in a backward-wave magnetron.

A telemeter that employs the magnitude of a single voltage as the translating procedure.