"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"
'Aa' to 'Af', 'Ag' to 'Al', 'Am' to 'Am',
'An' to 'Ao', 'Ap' to 'As', 'At' to 'Az',
APPARENT DRIFT. The effect of the earth’s rotation on a gyro that causes the spinning axis to appear to make one complete rotation in one day.
APPARENT POWER. That power apparently available for use in an ac circuit containing a reactive element. It is the product of effective voltage times effective current expressed in volt-amperes. It must be multiplied by the power factor to obtain true power available.
ARBITRATION. The process of selecting one communication node on a bus over another.
ARC. A visible electrical discharge between separated contacts.
ARCHITECTURE. Defines how a system is connected or interconnected and in some cases how the components are interconnected.
ARMATURE. In a relay, the movable portion of the relay. The windings in which the output voltage is generated in a generator or in which input current creates a magnetic field that interacts with the main field in a motor.
ARMATURE LOSSES. Copper losses, eddy current losses, and hysteresis losses that act to decrease the efficiency of armatures.
ARMATURE REACTION. The effect in a dc generator of current in the armature creating a magnetic field that distorts the main field and causes a shift in the neutral plane.
ARMOR. A flexible metal 'shield' that protects a component from damage. Refer to Cable Armor definition.
| ARRAY. A group of devices or components. A number of devices contained within a single package, but not connected to each other. Also see Transistor Arrays. Types of Diode Arrays, or Resistor Arrays. Graphic; Transistor Array in an LCC package. Also see Antenna Array [within the Antenna Dictionary]. |
 Transistor Array |
| ARMSTRONG OSCILLATOR. A type of oscillator. The ARMSTRONG OSCILLATOR is used to produce a sine-wave output of constant amplitude and
of fairly constant frequency within the rf range. Types of Oscillator Vendors. |
 Armstrong Osc |
ASCII. The American Standard Code for Information Interchange. A common method used by computers to code alphabetic letters into a binary code. Refer to table of ASCII Codes.
ASPECT RATIO. The ratio between the width of an object and the height of the object.
ASSEMBLY. A number of parts or subassemblies, or any combination thereof, joined together to perform a specific function. As in a Printed Wiring Board Assembly, which comprises the Printed Wiring Board [PWB] and all the components attached to the PWB. Also refer to PWB Terms [within the PCB Dictionary].
ASTABLE MULTIVIBRATOR. A multivibrator that has no stable state. Also called free-running because it alternates between two different output voltage levels during the time it is on. The frequency is determined by the RC time constant of the coupling circuit. Also refer to a 555 Astable Circuit, or Transistor Astable Multivibrator Circuit.
Astable Multivibrator
ASTIGMATISM. An aberration of a lens with spherical surfaces such that the image of a point not lying on the optical axis is a pair of short lines normal to each other and at slightly different distances from the lens. Radial and tangential lines are in focus in different image planes.
ASYMMETRICAL MULTIVIBRATOR. A multivibrator that generates rectangular waves.
ASYNCHRONOUS COMMUNICATION. Communication in which no clocking information is passed between stations.
ASYNCHRONOUS LOGIC. A Digital circuit whose output only depends on the combination logic gates used and the propagation delay through those gates. A logic circuit that does not use a Flip Flop or other synchronizing element.
ASYNCHRONOUS TRANSMISSION. Parallel Information is synchronized individually [per transfer] by hand-shaking as in DAV [Data Available] and DAC [Data Accepted], or REQ and ACK lines. Serial Information is synchronized individually [per block] via 'START' and 'STOP' bits. Information is passed between nodes with out a separate clock signal to indicate when data on the transmission line is valid.
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