18WuD2x

116 circuit diagram • circular magnetic wave
SCHEMATIC, SCHEMATIC DIAGRAM, and
WIRING DIAGRAM.
circuit dropout A momentary interruption of circuit
operation, often caused by a break in the circuit.
circuit efficiency A quantitative measure of the
effectiveness of circuit operation, customarily expressed
as the ratio of the useful output power to
the total input power.
circuit element See CIRCUIT COMPONENT, 1.
circuit engineer An electronics engineer who specializes
in circuit analysis, circuit synthesis, or
both.
circuit fault 1. Malfunction of a circuit. 2. An error
in circuit wiring.
circuit hole A perforation within the conductive
area of a printed-circuit board, for the insertion
and connection of a pigtail, terminal, etc., or for
connecting the conductors on one side of the
board with those on the other.
circuit loading Intentionally or unintentionally
drawing power from a circuit.
circuit noise 1. Electrical noise generated by a circuit
in the absence of an applied signal. 2. In wire
telephony, electrical noise as opposed to acoustic
noise.
circuit noise level The ratio of circuit-noise amplitude
to reference-noise amplitude, expressed in
decibels above the reference amplitude.
circuit-noise meter A meter that measures the intensity
of the noise generated within a circuit.
circuit parameter See CIRCUIT COMPONENT, 2.
circuit protection Automatic safeguarding of a
circuit from damage from overload, excessive
drive, heat, vibration, etc. Protection is afforded
by various devices and subcircuits, ranging from
the common fuse to sophisticated limiters and
breakers.
circuit reliability A quantitative indication of the
ability of a circuit to provide dependable operation
as specified. See MEAN TIME BEFORE FAIL-
URE and MEAN TIME BETWEEN FAILURES.
circuitry 1. Collectively, electronic and electrical
circuits. 2. A detailed plan of a circuit and its
subcircuits. 3. Collectively, the components of a
circuit.
circuit schematic See CIRCUIT DIAGRAM.
circuit simplification 1. In circuit analysis, the
reduction of a complex circuit to its simplest representation
to minimize labor and to promote
clarity. Thus, through application of Kirchhoff’s
laws, a complicated circuit could theoretically be
reduced to a single generator in series with a single
impedance. 2. In circuit synthesis, the arrangement
of a circuit so as to provide desired
performance with the fewest components and
least-complex wiring.
circuit switching In telephony, a method of connection
in which a single circuit is maintained between
two subscribers for the entire duration of
the call. The signal path does not change. The
connection is maintained even during periods of
silence (no data transmitted by either subscriber).
Compare PACKET SWITCHING.
circuit synthesis The development of a circuit under
the guidance of theoretical or practical knowledge
of basic electronics principles and
component parameters. Compare CIRCUIT
ANALYSIS.
circuit tester An instrument for checking the performance
of electronic circuits. Often consists of
a specialized continuity tester, but occasionally it
includes a dynamic performance tester.
circuit tracking The alignment and/or pretuning
of circuits for identical or optimum response. It
applies especially to cascaded circuits, whose
variable elements, such as tuned inductancecapacitance
(LC) networks, must follow each
other in step when ganged together.
circular angle The angle described by a radius vector
as it rotates counterclockwise around a circle.
circular antenna A half-wave horizontally polarized
antenna, whose driven element is a rigid
conductor bent into a circle with a break opposite
the feed point. Also called halo antenna. Used primarily
at very-high frequencies (VHF).
circular electric wave An electromagnetic wave
with circular electric lines of flux. An example is
the field in the immediate vicinity of a CIRCULAR
ANTENNA.
Loop
carrying ac
circular electric wave
Electric lines
of flux
circular functions Trigonometric functions of the
angle described by a vector rotating counterclockwise
around a circle. Also see COSINE,
COSECANT, COTANGENT, SECANT, SINE, and
TANGENT.
circular magnet See RING MAGNET.
circular magnetic wave An electromagnetic wave
in which the magnetic lines of flux are circular.
An example is the field in the immediate vicinity
of a straight-conductor antenna.