18WuD2x

cold rolling • collector voltage 125
cold rolling A method of manufacturing an inductor
core so that the magnetic grains are all arranged
lengthwise.
cold solder joint A solder joint in which insufficient
heat has been applied, resulting in a bad
connection.
cold spot 1. An area of a circuit or component
whose temperature is ordinarily lower than that
of the surrounding area. 2. A node of current or
voltage. Compare HOT SPOT.
cold weld A welded joint produced by means of
COLD PRESSURE WELDING.
colidar An optical radar system using unmodulated,
coherent (laser-produced) light. The term is
an acronym for coherent light detection and
ranging.
collate In data processing, to produce an ordered
set from two or more similarly ordered sets (as
punched cards).
collator In a punched-card system, a device that
collates (see COLLATE) punched cards.
collector 1. In a bipolar transistor, the electrode
toward which emitted current carriers travel. 2.
In a Klystron, the final electrode toward which
electrons migrate after passing through the
buncher and catcher. 3. In an iconoscope, a
cylindrical electrode around the circumference of
the tube, which gathers and conducts away the
electrons released by the mosaic. 4. The final (target)
electrode in a backward-wave or travelingwave
tube. 5. A computer program segment that
collates compiled segments so that they can be
loaded into the computer.
collector capacitance 1. Symbol, C C . The capacitance
of the collector junction in a bipolar transistor.
2. The capacitance of the collector
electrode in a Klystron, iconoscope, backwardwave
tube, or traveling-wave tube.
collector current 1. Symbol, I C . The current flowing
in the collector circuit of a bipolar transistor.
Also see AC COLLECTOR CURRENT and DC
COLLECTOR CURRENT. 2. Current flowing in
the collector circuit of a Klystron, iconoscope,
backward-wave tube, or traveling-wave tube.
collector-current cutoff See COLLECTOR CUT-
OFF.
collector cutoff In a bipolar transistor, the condition
in which the collector current is cut off (i.e.,
reduced to the residual value). Also see CUTOFF
CURRENT.
collector cutoff current See CUTOFF CURRENT.
collector-diffusion isolation A method of making
integrated circuits that contain bipolar
transistors. Provides electrical separation of
the transistors in a semiconductor integrated
circuit.
collector dissipation Symbol, P C . In a bipolar
transistor, the power dissipation of the collector
electrode. The collector dc power dissipation is
the product of collector current and collector voltage:
P C = V C I C .
collector efficiency In a bipolar transistor circuit,
the ratio of ac power output to dc collector-power
input.
collector family For a bipolar transistor, a group
of collector current versus collector voltage
curves. Each is plotted for a particular value of
base current (common-emitter circuit) or emitter
current (common-base circuit).
I C
}
Various
values
of
base
voltage
or
current
(E B or
I B )
Collector current
Collector voltage
collector family
collector junction In a bipolar transistor, the
junction between collector and base layers.
collector mesh In a cathode-ray storage tube, a
flat, fine wire screen that attracts and conducts
away the secondary electrons knocked out of the
storage mesh by the electron beam.
collector multiplication In a bipolar transistor,
an increase in the number of electrons at the collector
electrode, caused by a momentary alteration
of the charge density of the collector
junction by injected carriers reaching the junction.
collector resistance In a bipolar transistor, the internal
resistance of the collector junction. See AC
COLLECTOR RESISTANCE and DC COLLECTOR
RESISTANCE.
collector ring 1. A rotating, brush-contacted ring
electrode connected to one end of a coil in an ac
generator. 2. A similar ring which, with a brush,
serves as a connection to a rotating element, as in
a signal-gathering system. 3. The collector electrode
in an iconoscope.
collector transition capacitance The capacitance
between the collector and base of a bipolar transistor
under normal operating conditions. This
capacitance has a limiting effect on the operating
frequency of a bipolar device.
collector voltage Symbol, V C . In a bipolar transistor,
the voltage on the collector electrode. See AC
E C