18WuD2x

52 automatic secure voice communications • auxiliary contacts
to a security network that provides encoded voice
communications.
automatic send/receive set A teletypewriter or
terminal that is capable of receiving and transmitting.
automatic sensitivity control 1. A self-actuating
circuit using principles similar to those used in
AUTOMATIC GAIN CONTROL. It varies the sensitivity
of the radio-frequency (RF) and intermediate-frequency
(IF) sections of a receiver in inverse
proportion to the strength of a received signal. 2.
In a bridge null detector, a circuit similar to the
one described in 1, which operates ahead of the
detector, varying the sensitivity of the latter automatically.
automatic sequencing The ability of a digital computer
to perform successive operations without
additional instructions from the operator.
automatic short-circuiter A device that automatically
short-circuits the commutator bias in some
single-phase commutator motors.
automatic short-circuit protection A circuit that
allows the output of a power supply to be shortcircuited
without damage to the components
in the supply. It usually consists of a currentlimiting
device.
automatic shutoff A switching arrangement that
automatically shuts off a device or circuit under
certain specified conditions.
automatic switch center A telephone-switching
network that routes calls to their destinations
without the need for a human operator.
automatic target control For a vidicon television
camera tube, a circuit that automatically adjusts
the target voltage in proportion to brightness of
the scene.
automatic telegraph reception Telegraph reception
providing a direct printout of the received information,
without intervention by an operator.
automatic telegraph transmission Telegraph
transmission originating from tapes, disks, or other
records, rather than from a hand-operated key.
automatic telegraphy Communications that utilize
automatic telegraph transmission and reception.
automatic time switch A time-dependent circuit
or device that opens or closes another circuit at
the end of a predetermined time interval.
automatic tracking A method of keeping a radar
beam automatically fixed on a target.
automatic trip A circuit breaker that automatically
opens a circuit.
automatic tuning A process whereby a circuit
tunes itself to a predetermined frequency upon
receiving a command signal.
automatic voltage regulator A circuit that keeps
the output of a power supply constant, despite
the load resistance or input voltage to the supply.
automatic volume control Abbreviated AVC. The
use of AUTOMATIC GAIN CONTROL in an audio
amplifier system.
automatic zero In an electronic meter, a means of
automatically setting the indicator to zero in the
absence of an input signal.
automation 1. The control of machines or processes
by self-correcting electronic systems. See
ROBOT. 2. The use of robots and/or computers,
rather than human beings, to perform repetitive
tasks. 3. The use of robots and/or computers to
assist human beings in industrial, office, governmental,
and educational work.
automaton A simple robot that performs a task or
set of tasks without artificial intelligence (AI).
These machines have existed for decades. Compare
ANDROID.
automonitor In digital computer operations, to require
the machine to supply a record of its information-handling
operations. Also, the program
for such instructions.
automotive battery A set of four or eight
rechargeable lead-acid cells connected in series
and housed in a common enclosure. The electrolyte
is a free-flowing liquid acid. Provides approximately
6 volts (four cells) or 12 volts (eight
cells) under no-load conditions when fully
charged. The high mass results in large energystorage
capacity. These batteries must be handled
with care and always kept in an upright
position to prevent spillage of the acid. See
LEAD-ACID BATTERY, LEAD-ACID CELL.
autonomous robot A self-contained robot with an
independent computerized control system. It
moves under its own power, usually by rolling on
wheels or a track drive. Compare INSECT ROBOT.
autopatch A remotely controllable device that interconnects
a radio-communications system into
a telephone network.
autopilot A self-correcting control and guidance
device for the automatic management of an aircraft
or missile.
autoranging See AUTOMATIC RANGING.
autosyn A device or system that operates on the
principle of the synchronous ac motor, in which
the position of the rotor in one motor (the transmitter)
is assumed by the rotor in a distant motor
(the receiver) to which the first is connected.
auto tracking A method of controlling the output
voltages of many different power supplies simultaneously.
autotransducter A type of magnetic amplifier
whose power windings serve also as control windings.
autotransformer A single-winding transformer in
which the primary coil is a fraction of the entire
winding for voltage step-up, or the secondary coil
is a fraction of the entire winding for voltage stepdown.
auxiliary circuit A circuit that is supplementary to
the main system.
auxiliary contacts In switches and relays, contacts
that are supplementary to the main contacts
and are usually actuated with them.