18WuD2x

96 can • capacitive coupling
can 1. A metal enclosure or container roughly resembling
a tin can (though not necessarily cylindrical),
used for shielding or potting components.
2. Colloquial expression for HEADPHONE.
Canada balsam A transparent cement derived
from the turpentine distilled from balsam fir
resin. It is useful in optical technology and in certain
areas of electro-optics.
Canadian Standards Association The Canadian
equivalent of the National Bureau of Standards in
the United States. An agency that publishes
agreed-on standards for industries.
cancel character 1. IGNORE CHARACTER. 2. A
control character indicating that the associated
data is erroneous.
cancellation The elimination of one quantity by
another, as when a voltage is reduced to zero by
another voltage of equal magnitude and opposite
sign.
candela Symbol, cd. The SI unit of luminous intensity;
1 cd represents 1⁄60 of the radiating power of
one square centimeter of a perfect radiator at the
temperature of freezing platinum.
candle Abbreviation, c. Also called international
candle. A unit of light intensity that is the value of
emission by the flame of a sperm-whale-oil candle
burning at the rate of 7.776 grams per hour.
candle power Abbreviation, cp. Luminous intensity
in international candles: the luminous intensity
resulting from the burning of a
sperm-whale-oil candle at 7.776 grams per hour.
candoluminescence White light produced without
extreme heat.
cannibalization The deliberate use of parts from
operational equipment to temporarily repair or
maintain other equipment. It is a last-resort,
emergency measure.
cap 1. Abbreviation of CAPACITANCE. 2. Abbreviation
of CAPACITOR.
capacimeter See CAPACITANCE METER.
capacitance Symbol, C. Unit, farad. The property
exhibited by two conductors separated by a dielectric,
whereby an electric charge becomes
stored between the conductors. Capacitance is
thought of as analogous to mechanical elasticity.
Also see FARAD.
capacitance bridge A four-arm ac bridge for gauging
capacitance against a standard capacitor. In
its simplest form, it has a standard capacitor in
one arm and resistors in the other three.
capacitance coupling The transfer of ac energy
between two circuits or devices by a capacitor or
capacitance effect. Also see COUPLING.
capacitance diode See VARACTOR.
capacitance divider An alternating-current voltage
divider that uses capacitors, rather than resistors.
It is used in certain oscillators, such as
the Colpitts type.
capacitance filter A filter consisting of only a
high-capacitance capacitor. Because the capacitor
cannot discharge instantaneously, it tends to
maintain its voltage and smooth out the ripples in
the voltage applied to it.
capacitance-inductance bridge A combination ac
bridge that can be used for either capacitance or
inductance measurement. Both capacitance and
inductance can be measured in terms of a standard
capacitance; however, some of these bridges
use standard inductors in the inductancemeasuring
mode.
capacitance meter A direct-reading meter for
measuring capacitance. In most available types, a
stable ac voltage is applied to the meter circuit, to
which an unknown capacitor is connected in series;
meter deflection is roughly proportional to
the reactance of the capacitor. Also called MI-
CROFARAD METER.
capacitance ratio In a variable capacitor, the ratio
of maximum to minimum capacitance.
capacitance relay A relay circuit that operates
from a small change in its own capacitance. It
consists of an RF oscillator whose tank capacitance
is very low. When a finger is brought near
the circuit’s short pickup antenna, the attendant
increase in capacitance detunes the oscillator,
activating the relay. Also called PROXIMITY RE-
LAY and PROXIMITY SWITCH.
capacitance-resistance bridge A combination ac
bridge that can be used for either capacitance or
resistance measurement. The unknown resistance
is measured against a standard resistor;
the unknown capacitance against a standard capacitor.
capacitance sensor See CAPACITANCE TRANS-
DUCER.
capacitive amplifier See DIELECTRIC AMPLI-
FIER.
capacitive attenuator An ac attenuator whose elements
are capacitors in any desired combination
of fixed and/or variable units. The desired attenuation
is afforded by the capacitance ratio.
capacitive coupling A means of coupling between
circuits that uses a series capacitor for directcurrent
blocking. The signal passes through the
capacitor, but the blocking effect allows different
bias voltages to be applied to the two stages.
+
capacitive coupling