Electronic Engineering Dictionary

Volt. The term used for electrical potential, or potential difference. The unit of electromotive force or electrical pressure. One volt is the pressure required to send 1 ampere of current through a resistance of 1 ohm.

Voltage. The term used to signify electrical pressure. Voltage is a force that causes current to flow through an electrical conductor. The voltage of a circuit is the greatest effective difference of potential between any two conductors of the circuit. The effective (rms) potential difference between any two conductors or between a conductor and ground.

Voltage Amplifier. An amplifier in which the output-signal voltage is greater than the input-signal voltage.

Voltage Break-Down. The voltage magnitude required to cause insulation failure.

Voltage Comparator. A circuit used to compare one or more voltages to another voltage. Typically a voltage comparator is accomplished by an Operation Amplifier, normally just called a comparator. Also refer to IC comparator manufacturers. An LM111 or LM119 Comparator. Read more about Voltage Comparators.

Voltage Controlled Oscillator. [VCXO] An oscillator that uses a external voltage to tune or change the frequency of the oscillator's output. Also refer to Voltage Controlled Oscillator Manufacturers.

Voltage Dependent Resistor. [VDR] Refer to the Varistor Definition.

Voltage Detector. A circuit used to detect a voltage level, or a level above a voltage threshold. The circuit to the right uses the sense line as the input and compares that to a precession voltage reference.

Voltage-Diode Detector. A series-diode detector in which the diode is in series with the input voltage and the load impedance.

Voltage Directional Relay. A relay that functions only when the input is above a certain value and in a given direction [diode input].

Voltage Divider. A series network in which desired portions of the source voltage may be tapped off for use in the circuit. Resistors R1 and R2 form the voltage divider, with the tapped point being between the two resistors. A voltage divide could consist of a number of different components, another common voltage divider could be formed by two capacitors in series. A Potentiometer could be used as a voltage divider by applying an input to the two ends and taking the output from the center tap and one end. Shunt Resistor applied to a Potentiometer.

R1/R2 Voltage Divider

Voltage Doubler. A rectifier circuit that outputs a DC voltage that is twice the peak voltage of the input AC voltage. The voltage doubler circuit rectifies each half cycle of the AC input voltage and combines the rectified voltages using the capacitor to produce twice the peak amplitude of the input AC voltage.

Voltage Droop. The reduction in a pulse level over the course of the pulse due to heavy loading. Read more on Voltage Droop.

Voltage Drop. The difference in voltage between two points. It is the result of the loss of electrical pressure as a current flows through a resistance. The loss of voltage between the input to a device and the output from a device due to the internal impedance or resistance of the device.

Voltage Feedback. A path that returns some percentage of a voltage to a previous portion in the circuit. The feedback may be positive or negative with respect to the input section.

Voltage-Feed Method. Same as End-Feed Method [Antenna Dictionary].

Voltage Follower. A buffer. A circuit having an output that follows the input. A voltage follower will have a high source impedance and a low output impedance [like any good amplifier] so the circuit does not effect either the input driver or output receiver. An operational amplifier designed as a voltage follower; LM102 and LM110. An operational Amplifier configured as a Voltage Follower.

Voltage Gain. The ratio of output voltage to input voltage in an amplifier.

Voltage Generator. A device used as a source of electrical power.

Voltage Level. The voltage at some point in a circuit compared to another.

Voltage Multipliers. Methods of increasing voltages; used primarily where low current is required. An arrangement of diodes used to increase a voltage level, as in a voltage doubler.

Voltage Quadrupler. Either a Full-wave or Half-Wave rectifier circuit that outputs a DC voltage that is four times the peak voltage of the input AC voltage. Read more on the types of Voltage Quadrupler Schematics.

Voltage Reference. A circuit or device that provides a precision voltage that is used as a reference by another circuit. Most voltage references will be fixed, but some may be adjustable [with out becoming a voltage regulator], having a third terminal. Refer here for a list of Voltage Reference IC Manufacturers.

Reference

There are two common types of IC voltage references; a 2-terminal Shunt reference [similar to a LM129] and a 3-terminal Series reference [similar to a LT1021], for example.

Ref Circuit

The most common symbol for a voltage reference is a Zener diode, which may also be found with a third terminal for adjustments [ADJ]. The actual circuit may be much more than a simple Zener diode. Both a schematic symbol and the physical circuit are shown as examples.

Voltage Regulation. A measure of the ability of a generator or power supply to maintain a constant output voltage from no-load to full-load operation. Expressed as a percentage of full-load voltage; the better the regulation, the lower the percent. [IC Voltage Regulators]

Voltage Regulator. A component or device that maintains or regulates an output voltage at a constant level in spite of large changes in load current or input line voltage. The two main styles include Switching Regulators and Linear Regulators. [Regulator Manufacturers]. A zener diode used to produce a constant voltage.

Voltage Spike. A voltage spike is a voltage change of very short duration (less than 1 ms). A voltage jump or abrupt increase in the voltage level of limited duration.

Voltage Standing Wave Ratio. [VSWR] In a waveguide, the ratio of the electric field (voltage) at a maximum point to that of an adjacent minimum point. Refer to the Radar Dictionary for a VSWR Table. The ratio of the maximum voltage amplitude to the minimum voltage amplitude measured along the path of the waves.

Voltage Stabilizer. See Voltage Regulator.

Voltage Transformer. An Instrument Transformer, used to provide accurate inputs to control systems.

Voltage Transient. A voltage transient (excluding voltage spikes) is a sudden change in voltage that goes outside the user voltage tolerance limits and returns to and remains within these limits within a specified recovery time (longer than 1 ms) after the initiation of the disturbance.

Voltage Tripler. A rectifier circuit that outputs a DC voltage that is three times the peak voltage of the input AC voltage.

Voltaic Cell. A combination of materials used to convert chemical energy into electrical energy. A voltaic or chemical cell consists of two electrodes made of different types of metals or metallic compounds placed in an electrolyte solution

Voltmeter. A meter used to measure voltage. Also see the list of Test Equipment Manufacturers.

Volt-Ohm Meter. [VOM] A meter used to measure either voltage or resistance.

VU Meter. [Volume Unit] A meter that indicates sound volume. Zero VU is 1mW on 600 ohms.