18WuD2x

200 discrete capacitor • disk capacitor
tributed. Also called LUMPED CAPACITOR. Compare
DISTRIBUTED CAPACITANCE.
discrete circuit A circuit comprised of discrete
components, such as resistors, capacitors,
diodes, and transistors, not fabricated into an integrated
circuit.
discrete component A self-contained device that
offers one particular electrical property in lumped
form (i.e., concentrated at one place in a circuit,
rather than being distributed). A discrete component
is built especially to have a specific electrical
property, and exists independently, not in combination
with other components. Examples: disk
capacitor, toroidal inductor, and carbon-composition
resistor. Compare DISTRIBUTED COMPO-
NENT.
discrete device Any component or device that operates
as a self-contained unit.
discrete element A discrete device that forms part
of a larger system.
discrete inductor An inductive component that is
entirely self-contained, rather than being electrically
spread out. Also called lumped inductor.
Compare DISTRIBUTED INDUCTANCE.
discrete information source A source of data containing
a finite number of individual elements,
rather than a continuously variable parameter.
discrete part See DISCRETE COMPONENT.
discrete resistor A resistive component that is entirely
self-contained, rather than being electrically
spread out. Also called lumped resistor.
Compare DISTRIBUTED RESISTANCE.
discrete sampling Sampling of individual bits or
characters, one or more at a time.
discrete thin-film component A discrete component
produced by the thin-film process (e.g., thinfilm
capacitor, thin-film potentiometer, etc.).
discretionary wiring A method of interconnecting
the components and circuits on a semiconductor
wafer for optimum performance. This requires a
separate analysis and wiring pattern for every
chip.
discrimination 1. Sharp distinction between electrical
quantities of different value. 2. The detection
of a frequency-modulated (FM) signal (i.e., the delivery
of an audio signal corresponding to the frequency
or phase variations in the FM carrier).
discriminator A second detector for frequencymodulated
(FM) signals, in which two diodes are
operated from the center-tapped secondary of a
special intermediate-frequency (IF) transformer.
The circuit is balanced for zero output when the
instantaneous received signal frequency is at the
unmodulated carrier frequency; the circuit delivers
output when the instantaneous received
signal frequency swings above or below the
unmodulated carrier frequency. Also see FOS-
TER-SEELEY DISCRIMINATOR and TRAVIS DIS-
CRIMINATOR.
discriminator transformer The special input
transformer in a DISCRIMINATOR.
From
limiter
C2
C1
T1
C3
D1
D2
discriminator tuner A device that tunes a discriminator
to a selected subcarrier.
discriminator tuning device See DISCRIMINA-
TOR TUNER.
dish See DISH ANTENNA.
dish antenna A transmitting and/or receiving antenna
consisting of a driven element and a large
reflector. The reflector has the shape of a shallow,
circular section of a paraboloid or sphere. The
feed point is at the focus of the reflector. This antenna,
noted for its high directivity and gain, is
used mainly at ultra-high and microwave frequencies
for communications and satellite television.
Large antennas of this type are used in
some radio telescopes.
dish-type construction A type of panel-and-chassis
construction in which the chassis is fastened
vertically to the back of the panel.
disintegration 1. The destructive breakdown of a
material. 2. The stripping of a vacuum-tube cathode
of its emissive coating (see DISINTEGRATION
VOLTAGE). 3. The decay of a radioactive material.
disintegration voltage The anode voltage at which
the cathode of a gas tube begins to be stripped of
its electron-emitting material. For safety and reasonable
tube life, the anode working voltage must
be between the ionization and disintegration values.
disintegrator An ultrasonic device for reducing
crystals or particles to fine suspensions.
disjunction The logical inclusive-OR operation.
disk 1. A flat, circular plate (e.g., rectifier disk). 2.
See DISKETTE. 3. See HARD DISK. 4. See COM-
PACT DISC. 5. See CD-ROM. 6. A phonograph
record or the equivalent unrecorded blank.
disk capacitor A fixed (usually two-plate) capacitor
consisting of a disk of dielectric material on
whose faces are deposited metal-film plates.
R1
R2
discriminator
disk capacitor
R3
C5
C6
C4
To AF
amp