Electronics (Mike Jaroch)


Note: You may download the entries for this glossary here. If you wish to use this in your own Moodle course, first make a blank glossary and then follow the instructions for importing glossary entries here.

Browse the glossary using this index

Special | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | ALL

Page:  1  2  3  4  5  6  7  (Next)
  ALL

I

I2R LOSS

See COPPER LOSSES [11].

IC SYNCHROS

Obsolete synchros with reverse rotation and limited torque capabilities [15].

IDEMPOTENT LAW

In Boolean algebra, combining a quantity with itself either by logical addition or logical multiplication will result in a logical sum or product that is the equivalent of the quantity (for
example, A + A = A; A • A = A) [13].


IDENTITY LAW

In Boolean algebra, the law which states that any expression is equal to itself

IDLER FREQUENCY

In a parametric amplifier, the difference between the input signal and the pump signal frequency. Also called the LOWER-SIDEBAND FREQUENCY [11].


IF AMPLIFIER

Usually a narrow-bandwidth IF amplifier that is tuned to one of the output frequencies produced by the mixer [18].


IGFET

Any field-effect transistor that has an insulated gate [7].

IMAGE FREQUENCY

An undesired frequency capable of producing the desired frequency through
heterodyning [17].


IMPEDANCE

The total opposition offered to the flow of an alternating current. It may consist of any combination of resistance, inductive reactance, and capacitive reactance. The symbol for impedance is Z [2] [9].


IMPLOSION

The inward bursting of a CRT because of high vacuum. The opposite of explosion [6].

IN PHASE

Applied to the condition that exists when two waves of the same frequency pass through their maximum and minimum values of like polarity at the same instant [2].


IN-CIRCUIT METER

A meter permanently installed in a circuit; used to monitor circuit operation [3].

INCIDENT WAVE

(1) The wave that strikes the surface of a medium. (2) The wave that travels from the sending end to the receiving end of a transmission line [10].


INCOHERENT

Refers to radiation on a broad band of frequencies [17].

INDEX OF REFRACTION

The degree of bending of an RF wave when passing from one medium to
another [18].


INDICATOR

Equipment in radar that provides a visual presentation of target position information [18].

INDIRECTLY HEATED CATHODE

Same as the directly heated cathode with one exception: The hot filament raises the temperature of the sleeve around the filament; the sleeve then becomes the electron emitter [6].


INDUCED CHARGE

An electrostatic charge produced on an object by the electric field that surrounds a nearby object [1].


INDUCED CURRENT

Current caused by the relative motion between a conductor and a magnetic field [1].


INDUCED ELECTROMOTIVE FORCE

The electromotive force induced in a conductor because of the relative motion between the conductor and a magnetic field [1].


INDUCED VOLTAGE

See INDUCED ELECTROMOTIVE FORCE [1].

INDUCED-CHANNEL MOSFET

A MOSFET in which there is no actual channel between the source and the drain. This MOSFET is constructed by making the channel of the same type of material as the substrate [7].


INDUCTANCE

The property of a circuit that tends to oppose a change in the existing current flow. The symbol for inductance is L [2] [7].


INDUCTANCE BRIDGE

An ac bridge circuit used to measure an unknown value of inductance [16].

INDUCTION

The act or process of producing voltage and current by the relative motion of a magnetic field across a conductor [1].


INDUCTION FIELD

The electromagnetic field that is produced about an antenna when current and
voltage are present on the same antenna [10].


INDUCTION LOSSES

The losses that occur when the electromagnetic field around a conductor cuts
through nearby metallic objects and induces a current into that object [10].


INDUCTION MOTOR

A simple, rugged, ac motor with desirable characteristics. The rotor is energized by transformer action (induction) from the stator. Induction motors are used more than any other type [5].


INDUCTIVE COUPLING

Coupling of two coils by means of magnetic lines of force. In transformers,
coupling applied through magnetic lines of force between the primary and secondary windings [2].


INDUCTIVE REACTANCE

The opposition to the flow of an alternating current caused by the inductance of a circuit, expressed in ohms. Identified by the symbol X L [2] [9].


INERTIA

The physical tendency of a body in motion to remain in motion and a body at rest to remain at rest unless acted upon by an outside force (Newton's First Law of Motion) [15].


INFINITE

(1) Extending indefinitely, endless. (2) Boundless, having no limits. (3) An incalculable number [1].


INFRALOW FREQUENCY

The band of frequencies from 300 Hz to 3,000 Hz [19].

INFRASONIC

Sounds below 15 Hz [10].

INPUT

The current, voltage, power, or driving force applied to a circuit or device [13].

INPUT END

The end of a two-wire transmission line that is connected to a source [10].

INPUT IMPEDANCE

Impedance presented to the transmitter by the transmission line and its load [10].

INSTANTANEOUS AMPLITUDE

The amplitude at any given point along a sine wave at a specific instant in time [12].


INSTANTANEOUS AUTOMATIC GAIN CONTROL

A circuit that can vary the gain of the radar receiver with each input pulse to maintain a nearly constant output peak amplitude [18].


INSTANTANEOUS VALUE

The magnitude at any particular instant when a value is continually varying
with respect to time [2].


INSULATION

A material used to prevent the leakage of electricity from a conductor and to provide mechanical spacing or support as protection against accidental contact with the conductor [1] [4].


INSULATION RESISTANCE

The resistance offered by an insulating material to current leakage [4].

INSULATOR

(1) Material of such low conductivity that the flow of current through it can usually be neglected. (2) A device having high electrical resistance; used for supporting or separating conductors so as to prevent undesired flow of current from the conductors to other objects [1].


INTEGRATED CIRCUIT

(1) A circuit in which many elements are fabricated and interconnected by a single process (into a single chip), as opposed to a "nonintegrated" circuit in which the transistors, diodes, resistors, and other components are fabricated separately and then assembled [7]. (2) Elements inseparably associated and formed on or within a single substrate [14].


INTELLIGENCE

In communications any signal that conveys information (voice, teletypewriter,
facsimile) [17].


INTENSITY

INTENSITY (OF SOUND)—The measurement of the amplitude of sound energy. Generally synonymous with loudness [10].


INTERACTION SPACE

The region in an electron tube where the electrons interact with an alternating
electromagnetic field [11].


INTERCEPT

The point where two lines drawn on a graph cross each other [10].

INTERELECTRODE CAPACITANCE

The capacitance between the electrodes of an electron tube [6] [11].


INTERFERENCE

Any disturbance that produces an undesirable response or degrades a signal [10].

INTERMEDIATE FREQUENCY

A lower frequency to which an RF echo is converted for ease of amplification [18].


INTERMEDIATE POWER AMPLIFIER

The amplifier between the oscillator and final power amplifier [12].


INTERMEDIATE-LEVEL MAINTENANCE

Direct support and technical assistance to user organizations. Tenders and shore-based repair facilities [14].


INTERPOLES

Small auxiliary poles, placed between main field poles, whose magnetic field opposes the armature field and cancels armature reaction. Interpoles accomplish the same thing as compensating windings [5].


INTERSECTION LAW

In Boolean algebra, the law which states that if one input to an AND gate is
already TRUE, then the output will depend upon the state of the other inputs only [13].


INVERSELY

Inverted or reversed in position or relationship [1].

INVERT

To change a physical or logical state to its opposite state [13].

INVERTER

A circuit with one input and one output. Its function is to invert or reverse the input. When the input is high, the output is low, and vice versa. The inverter is sometimes called a NOT circuit, since it produces the reverse of the input [13].


ION

An electrically charged atom or group of atoms. Negative ions have an excess of electrons; positive ions have a deficiency of electrons [1].


IONIZATION

(1) The process of producing ions. (2) The electrically charged particles produced by high-energy radiation, such as light or ultraviolet rays, or by the collision of particles during thermal agitation [6] [10].


IONIZATION POINT

The potential required to ionize the gas of a gas-filled tube. Sometimes called
firing potential [6].


IONIZE

To make an atom or molecule of an element lose an electron, as by X-ray bombardment, and thus be converted into a positive ion. The free electron may attach itself to a neutral atom or molecule to form a negative ion [1].


IONOSPHERE

The most important region of the atmosphere extending from 31 miles to 250 miles above sea level. Contains four cloud-like layers that affect radio waves [10].


IONOSPHERIC STORMS

Disturbances in the earth's magnetic field that make communications practical only at lower frequencies [10].


IRIS

A metal plate with an opening through which electromagnetic waves may pass. Used as an impedance-matching device in waveguides [11].


ISOLATION

The prevention of unwanted interaction or leakage between components [14].

ISOMETRIC DIAGRAM

A diagram showing the outline of a ship, aircraft, or equipment and the
location of equipment and cable runs [4].


ISOTROPIC RADIATION

The radiation of energy equally in all directions [10].


Page:  1  2  3  4  5  6  7  (Next)
  ALL