GLOSSARY
ACCELEROMETER --A device that measures
APPARENT DRIFT --The effect of the
the acceleration to which it is subjected and
earth's rotation on a gyro that causes the spinning
axis to appear to make one complete rotation in
develops a signal proportional to it.
1 day. Also called APPARENT PRECESSION
AGONIC --An imaginary line of the earth's
or APPARENT ROTATION.
surface passing through points where the magnetic
declination is 0O degrees; that is, points where the
APPARENT PRECESSION --See APPAR-
compass points to true north.
ENT DRIFT.
AMBIENT CONDITIONS --Physical condi-
APPARENT ROTATION --See APPARENT
tions of the immediate environment, which may
DRIFT.
pertain to temperature, humidity, pressure, etc.
ARC --A flash caused by an electric current
AMPERE --The basic unit of electrical
ionizing a gas or vapor.
current.
ARMATURE --The rotating part of an elec-
AMPERE-TURN --The magnetizing force
tric motor or generator. The moving part of a
produced by a current of 1 ampere flowing
relay or vibrator.
through a coil of 1 turn.
A M P L I D Y N E --A rotary magnetic or
ATTENUATOR --A network of resistors
dynamoelectric amplifier used in servomechanism
used to reduce voltage, current, or power delivered
and control applications.
to a load.
AMPLIFICATION --The process of increasing
ATTRACTION --The force that tends to
the strength (current, power, or voltage) of a
make two objects approach each other. Attraction
signal.
exists between two unlike magnetic poles
(north and south) or between two unlike static
AMPLIFIER --A device used to increase the
charges.
signal voltage, current, or power, generally
composed of solid-state circuitry called a stage.
AUTOTRANSFORMER --A transformer in
It may contain several stages in order to obtain
which the primary and secondary are connected
a desired gain.
together in one winding.
AMPLITUDE --The maximum instantaneous
AVB --Avionic bulletin.
value of an alternating voltage or current,
measured in either the positive or negative
AVC --Avionic change.
direction.
AXIS --A straight line, either real or
ANALOG COMPUTER --A type of computer
imaginary, passing through a body around which
that provides a continuous solution to a mathe-
the body revolves.
matical problem with continuously changing
inputs. Inputs and outputs are represented by
AZIMUTH --Angular measurement in the
physical quantities that may be easily generated
horizontal plane in a clockwise direction.
or controlled.
