18WuD2x

cascaded carry • cathode 103
cascaded carry In digital computer practice, a system
of performing the carry operation (see
CARRY) in which the n + 1 place receives a carry
pulse only when the nth place has received carry
information to generate the pulse.
cascade thermoelectric device A thermoelectric
component or circuit that consists of several cascaded
sensors (see CASCADE, 1).
cascade voltage doubler A voltage-doubler circuit
(see VOLTAGE DOUBLER) consisting of two
diode-capacitor combinations in cascade. Unlike
the conventional voltage-doubler circuit with two
capacitors in the output, the cascade voltage doubler
has one in the input and one in the output.
cascode A high-gain, low-noise, high-inputimpedance
amplifier circuit, consisting of a
grounded-emitter or grounded-source input stage
coupled directly to a grounded-base or groundedgate
output stage.
In
cascode
(field-effect transistor
arrangement)
Out
case temperature The temperature at a designated
point on the outside surface of a component’s
case or housing.
Cassegrain antenna A dish antenna that uses
CASSEGRAIN FEED.
Main dish
Feed
Cassegrain antenna
Semisphere
focus reflector
Cassegrain feed A dish-antenna feed system in
which the feed point is located at the center of the
dish itself. For transmission, the radio-frequency
energy emerges from a waveguide and is directed to
a small convex reflector at the focal point of the
dish. The small reflector directs the signal back to
the dish, spreading the energy out to cover the entire
surface of the dish. The dish reflects the energy
again and collimates it in the desired direction of
propagation. For reception, the process is reversed;
the dish focuses the energy on the small reflector,
which propagates it back to the feed point.
cassette 1. A holder (magazine) of reels of magnetic
tape that is itself a mechanical subassembly,
which can be easily inserted into and
removed from a tape deck. 2. A lightweight holder
of photographic film or X-ray plates (before, during,
and after exposure).
castor oil A viscous insulating oil extracted from
castor beans. Highly refined castor oil is used as
an impregnant in some oil-filled capacitors. Dielectric
constant, 4.3 to 4.7. Dielectric strength,
380 V/mil.
CAT Abbreviation of COMPUTERIZED AXIAL TO-
MOGRAPHY.
catalysis The process whereby an agent, called a
catalyst, enhances a chemical reaction without
entering into the reaction. Catalysts are used in
electronics, for example, to promote the setting of
resins in potting and encapsulating operations.
catalytic agent A substance that accomplishes
catalysis.
cataphoresis As caused by the influence of an
electrostatic field, the migration toward the cathode
of particles suspended in a liquid.
catastrophic failure 1. Sudden, unexpected failure
of a component or circuit. 2. Failure that can
result in the breakdown of an entire system. Also
called catastrophic breakdown.
catcher In a Klystron, the second reentrant cavity.
(See KLYSTRON.)
catcher diode A diode that is connected to regulate
the voltage at the output of a power supply. The
cathode is connected to a source of reference voltage.
If the anode, connected to the source to be
regulated, becomes more positive than the cathode,
the diode conducts and prevents the regulated
voltage from rising more than 0.3 volt above
the reference voltage (for germanium diodes) or 0.6
volt above the reference voltage (for silicon diodes).
catcher grids In a Klystron, the grids through
which the bunched electrons pass on their way
from the buncher to the collector. Catcher grids
absorb energy from the bunched electrons and
present it to the collector circuit.
category In a computer system, a group of magnetic
disk volumes containing information related
by a common application.
category storage A computer-file storage section
that contains a number of categories and used by
an operating system.
catenation See CONCATENATION.
cathode 1. The negative electrode of a device (i.e.,
the electrode from which electrons move when a