18WuD2x

130 commercial-level security • common-mode input capacitance
commercial-level security See LEVEL-2 SECU-
RITY.
commercial killer A usually remote-controlled,
electronic relay for disabling a radio or television
receiver during advertisements.
commercial language A computer programming
language for commercial applications (payroll, for
example).
common 1. Grounded. 2. Pertaining to a connection
shared by several different points in a circuit
or system. 3. See COMMON GROUND.
common area A computer storage area usable by
several programs or segments within a program.
common-base circuit A bipolar transistor circuit
in which the transistor base is the common (or
grounded) electrode. Also called grounded-base
circuit.
common battery 1. A battery shared by two or
more different circuits or pieces of equipment. 2.
In wire telephony, a central office battery that
supplies the entire system.
common-battery office In wire telephony, a central
office that provides a common battery.
common business-oriented language See COBOL.
common-capacitor coupling The process of coupling
one tuned circuit to another by means of a
capacitor that is common to both circuits.
Input
L1
C1
C3
C2
(Common
capacitor)
L2
common-capacitor coupling
Output
common-carrier fixed station A fixed radio station
that provides public service.
common-cathode circuit A tube circuit in which
the cathode is the common (or grounded) electrode.
Also called grounded-cathode circuit.
common-channel interference Radio interference
resulting from two stations transmitting on the
same channel. It is characterized principally by
beat-note (heterodyne whistle) generation, and
suppression or capture of the weaker signal by
the stronger one.
common-collector circuit A bipolar-transistor
circuit in which the collector is the common (or
grounded) electrode. Also called grounded-collector
circuit and EMITTER FOLLOWER.
common communications carrier A communications
company authorized by the licensing agency
to furnish public communications.
common-component coupling See COMMON-
CAPACITOR COUPLING, COMMON-INDUCTOR
COUPLING, and COMMON-RESISTOR COU-
PLING.
common-drain circuit A field-effect transistor circuit
in which the drain terminal is the common
(or grounded) electrode. Also called groundeddrain
circuit and SOURCE FOLLOWER.
common-emitter circuit A bipolar transistor circuit
in which the emitter is the common (or
grounded) electrode. Also called grounded-emitter
circuit.
common-gate circuit A field-effect transistor circuit
in which the gate is the common (or grounded)
electrode. Also called grounded-gate circuit.
common-grid circuit A tube circuit in which the
control grid is the common (or grounded) electrode.
Also called grounded-grid circuit.
common ground A single ground-point connection
shared by several portions of a circuit.
common impedance A single impedance shared
by parts of a circuit. Because currents from the
various parts flow through this impedance simultaneously,
coupling (desired or undesired) can
occur between them.
common-impedance coupling See COMMON-
CAPACITOR COUPLING, COMMON-INDUCTOR
COUPLING, and COMMON-RESISTOR COU-
PLING.
common-inductor coupling The process of coupling
one tuned circuit to another by means of an
inductor that is common to both circuits.
Input
L1
C1
C2
L2
(Common
inductor)
L3
common-inductor coupling
Output
common language A language recognized by all
the equipment in a data processing system.
common logarithm Abbreviation, log 10 . Also
called base-10 logarithm. A logarithm in which
the base number is 10. Also see LOGARITHM.
common mode Pertaining to signals or signal
components that are identical in amplitude and
duration.
common-mode characteristics In an operational
amplifier, characteristics denoting amplifier performance
when a common signal is applied to inverting
and noninverting inputs.
common-mode gain The voltage gain of a differential
amplifier with a common-mode input.
common-mode impedance input The impedance
between ground and one of the inputs of a differential
amplifier. Compare COMMON-MODE IN-
PUT IMPEDANCE.
common-mode input capacitance In a differential
amplifier, the internal capacitance of the
common-mode input circuit.