Electronic Engineering Dictionary

MOV. Metal Oxide Varistor. A resistor that changes value with applied voltage. A varistor may also be called a VDR [Voltage Dependent Resistor]. Varistors will have a negative voltage coefficient. MOV devices are used in parallel with the load. Read more on Varistor Details, or Varistor Manufacturers.

MOV

Moving Coil Speaker. A speaker with the moving diaphragm which is attached to a coil. May also be called a Dynamic Speaker.

Moving-Iron Meter Movement. Moving-Vane Meter Movement.

Moving-Vane Meter Movement. A meter movement that uses the magnetic repulsion of the like poles created in two iron vanes by current through a coil of wire; most commonly used movement for ac meters. This is an Obsolete terms, most meters being produce are digital, there is no meter movement.

Multichip Microcircuit. A microcircuit consisting of elements formed on or within two or more semiconductor chips which are separately attached to a substrate or package.

Multiconductor. More than one conductor, as in a cable. Two or more insulated conductors (solid or stranded) contained in a common covering or jacket. A Multi-conductor cable may be round [shown] or flat.

Multicouplers. Couplers that patch receivers or transmitters to antennas. They also filter out harmonics and spurious responses and impedance-match the equipment.

Multielectrode Tube. An electron tube normally classified according to its number of electrodes (the multi-electrode tube contains more than three electrodes). Vacuum Tube graphic

Multielement Array. An array that consists of one or more arrays and is classified as to directivity. Also refer to the Antenna Dictionary

Multiloop Servosystem. A servo-system that contains more than one servo loop; each loop is designed to perform its own function.

Multimeter. A single meter combining the functions of an ammeter, a voltmeter, and an ohmmeter. Test Equipment Manufacturers.

HP Multimeter

Multipath. The multiple paths a radio wave may follow between transmitter and receiver. The propagation phenomenon that results in radio signals reaching the receiving antenna by two or more paths. See the Multipath graphic part of the Antenna Dictionary.

Multiphase. Polyphase. Having more than one phase.

Multiple Function Gate. A logic gate that may be configured into a number of logic functions by changing the conditions on the input pins. The logic function shown below, depending on the inputs, acts as a buffer, inverter, 2-to-1 data selector, 2 input AND gate, 2 input OR gate, or a 2 input OR, NOR, AND, NAND with one inverted input line.

Multiple Function Logic Gate

Multiplexing. A method for simultaneous transmission of two or more signals over a common carrier wave. The T1 Interface uses multiplexing to transmit data over trunk lines. An IC circuit that transmits one of two signals from the input to the output, refer to IC Multiplexers. Multiplexing is used when driving many single channels to a remote location, but installing a separate line for each channel would be prohibitive.

Multiplication Factor. The number of times an input frequency is multiplied.

Multiplier. A circuit with an output that represents the magnitude or product of the inputs. An Analog Multiplier picture is shown to the right.

Multispeed Synchro Systems. Systems that transmit data at different transmission speeds; for example, dual-speed and tri-speed synchro systems. See synchro.

Multi-Turn Potentiometer. A variable resistor, Potentiometer, that requires more than one turn to move from least value to full resistance. Also refer to the resistor dictionary for the Definition of Potentiometer.

Multi-Unit Tube. An electron tube containing two or more units within the same envelope. The multi-unit tube is capable of operating as a single-unit tube, or each unit can operate as a separate tube.

Multivibrator. A form of relaxation oscillator which comprises two stages that are coupled so that the input of one is derived from the output of the other. Related topics include Transistor Multivibrator, or 555 Circuits.

Multivibrator Modulator. An astable multivibrator used to provide frequency modulation. The modulating af voltage is inserted in series with the base return of the multivibrator transistors to produce the frequency modulation.

Mutual Flux. The total flux in the core of a transformer that is common to both the primary and secondary windings. The flux links both windings.

Mutual Capacitance. The capacitance between two unconnected conductors or circuits. Mutual Capacitance picture to the right. Also refer to the capacitor dictionary for the Definition of Capacitive Coupling.

Mutual Inductance. A circuit property existing when the relative position of two inductors causes the magnetic lines of force from one to link with the turns of the other. The symbol for mutual inductance is M. Also refer to Transformer Manufacturers.

Mutual Interference. Interference between two or more electrical systems or sensors which effect the systems on a reciprocal basis.

Mylar Capacitor. A capacitor that uses mylar film as a dielectric. Also refer to the capacitor dictionary for the Definition of Dielectric.