18WuD2x

320 grid return • ground conduit
grid return The circuit path through which the
control grid of a vacuum tube is returned to
ground or to the negative grid bias supply.
grid-separation circuit A vacuum-tube circuit
in which the control grid is grounded. See
COMMON-GRID CIRCUIT.
grid swing The peak-to-peak variation of a grid
excitation signal.
grid tank A resonant inductance-capacitance circuit
operating in the control-grid circuit of a vacuum
tube. Compare PLATE TANK.
grid tank capacitance The capacitance required
to tune a GRID TANK to resonance.
grid tank inductance The inductance of the coil
in a GRID TANK.
grid tank voltage The alternating-current (ac)
voltage developed across the grid tank of a vacuum-tube
circuit.
grid tuning Tuning of a vacuum-tube circuit by
varying the capacitance, inductance, or both in
the GRID TANK.
grid voltage 1. Symbol, V G . The direct-current
(dc) bias voltage applied to the control grid of a
vacuum tube. 2. Symbol, V G(ac) . The voltage of
the radio-frequency (RF) or audio-frequency (AF)
signal in the grid circuit.
grille A covering for an acoustic speaker, used
primarily to protect the speaker cone, but also
for esthetic appeal.
grille cloth A durable fabric often used for
speaker grilles in high-fidelity sound systems. It
transmits sound at all audio frequencies, but
protects the speaker(s) and provides an attractive
physical appearance.
gripper See ROBOT GRIPPER.
grommet An elastic washer inserted through a
hole in a chassis to prevent accidental grounding
of a conductor or to reduce wear on a cord or
cable exiting the chassis.
groove 1. See KEYWAY. 2. The fine, spiral line
cut into a phonograph disc when it is manufactured.
groove angle On a phonograph disk, the angle
between the walls of the unmodulated groove.
Disk
surface
Disk
motion:
toward observer
θ
groove angle
θ = Groove angle
(usually 90°)
groove speed In a phonograph recording or reproducing
system, the speed of the cutter or needle,
with respect to the disc. The speed is greatest
near the outer edge of the disk, and least near the
center.
gross content The overall amount of data contained
in a message. It can be expressed in bits,
bytes, words, or other units.
gross index One of a pair of indexes, used to give a
reference in the fine index, a supplement; both
indexes are used to locate computer records in
storage.
gross-motion planning The method(s) that a robot
uses to navigate in a general area without running
into objects, knocking things over, falling
down stairs, or losing its balance. It is often performed
using a COMPUTER MAP of the work environment.
ground 1. The earth in relation to electricity and
magnetism. 2. An electrical connection to the
earth. 3. The return point in a circuit. 4. A shortcircuit
to the earth or to a circuit return point.
5. A short-circuit to the metal chassis, case, or
panel of a piece of equipment.
ground absorption The absorption (and resulting
loss) of radio-frequency electromagnetic energy
by the earth.
ground bus A conductor connected to an earth
ground, and to which devices in a system are individually
connected. The common ground points
(e.g., chassis) of the individual devices are not directly
connected to each other, so ground loops
are avoided. This scheme minimizes the probability
of ELECTROMAGNETIC INTERFERENCE to
or from the system. Compare GROUND LOOP.
A B C
Bus
ground bus
ground clamp A device that provides a mechanical
and electrical bond between a conductor and a
ground rod or pipe. It is generally capable of passing
a large amount of current.
ground clutter 1. In a surface-based radar system,
echoes from nearby buildings, hills, and
other objects, producing blips or blobs near the
center of the screen. 2. In radar operations, an interference
pattern on the screen, caused by accidental
grounding in the system.
ground conductivity The ease with which the
earth will carry electrical current. Saltwater has
the best conductivity; dark, moist soil and fresh
water (because of the mineral content) rate from
fair to good. Sandy soil has the poorest ground
conductivity.
ground conduit A pipe housing one or more
ground leads.