18WuD2x

dual diode • Duant electrometer 217
dual diode A discrete component consisting of two
diodes in one package.
dual-diversity receiver A receiver or receiver system
for DIVERSITY RECEPTION.
dual-diversity reception See DIVERSITY RECEP-
TION.
dual-emitter transistor A low-level silicon pnp
chopper transistor of the planar passivated epitaxial
type; it has two emitter electrodes.
dual-frequency calibrator A secondary frequency
standard providing two fundamental test frequencies
(e.g., 100 kHz and 1 MHz).
dual-frequency induction heater An induction
heater whose work coils carry energy of two different
frequencies. The coils heat the work either
simultaneously or successively.
dual gate
1. A digital integrated circuit (IC) consisting
of two logic gate units. 2. Pertaining to a
field-effect transistor (FET) with two gates or gate
electrode connections.
dual-gate FET A field-effect transistor with two
gate (input) electrodes.
dual-gate MOSFET A metal-oxide-semiconductor
field-effect transistor (MOSFET) with two gate (input)
electrodes.
dual-inline package Abbreviation, DIP. A flat,
molded integrated-circuit (IC) package having terminal
pins along both long edges.
dual-inline package
Case
Pins
duality 1. The condition of being dual (see DUAL).
This can be an aid in the design of certain circuits
requiring complementary parameters, e.g., current-operated
circuit analogs of voltage-operated
circuits. 2. See DUALITY OF NATURE.
duality of nature 1. Any of various situations in
which a phenomenon exhibits two distinct and
different natures. A commonly cited example is
the dual model of light. In some instances, visible
light behaves like a barrage of particles, but in
other environments it appears to be a wave effect.
Another example is the dual model of electro-
static energy, behaving as point charges in some
scenarios and as force fields in other situations.
2. The tendency of a set of principles to be duplicated
in sense by predictable analogies, as between
inductance and capacitance, electrostatics
and magnetics, etc.
dual local oscillator See DOUBLE LOCAL OSCIL-
LATOR.
dual meter A meter having two meter movements
and scales in a single case; the arrangement permits
simultaneous monitoring of two quantities.
dual modulation The modulation of a single carrier
or subcarrier by two different types of modulation—each
carrying different information.
dual network A network that is the dual of another
network having complementary parameters. For
example, a common-emitter, current-sensitive,
bipolar-transistor circuit is the dual of a common-source,
voltage-sensitive, field-effect-transistor
(FET) circuit. Also see DUALITY.
dual operation In digital logic, the operation resulting
from inverting all of the digits. Every 1 is
replaced with a 0, and vice versa.
dual-output power supply A power supply with
two outputs. Often, one output is positive and the
other is negative. In some cases, one output consists
of alternating current (ac) and the other consists
of direct current (dc).
dual pickup In disk reproduction, a pickup having
two styli, one for large-groove records and one for
fine-groove records.
dual potentiometer A ganged assembly of two potentiometers.
The resistance values might or
might not be the same.
dual preset counter A preset counter that will set
alternately to two different numbers.
dual rail See DOUBLE RAIL.
dual resistor See DUAL POTENTIOMETER and
DUAL RHEOSTAT.
dual rheostat A ganged assembly of two rheostats.
The resistance values might or might not
be the same.
dual stereo amplifier 1. A two-channel audio amplifier
for stereophonic audio applications. 2. A
two-channel linear integrated circuit (IC) for
stereophonic audio applications.
dual-system loudspeaker See TWO-WAY
SPEAKER.
dual trace In a cathode-ray oscilloscope, the use of
two separate electron beams, which can show two
different signals simultaneously on a single
screen.
dual-trace recorder See DOUBLE-TRACK RE-
CORDER, 2.
dual-track recorder See DOUBLE-TRACK RE-
CORDER.
dual recording In digital computer operations, updating
two sets of master files simultaneously.
dual use The use of a communications system for
two modes of data transfer at the same time.
Duant electrometer See BINANT ELECTROMETER.