18WuD2x

dynamic decay • dynamic range 221
dynamic decay Decay resulting from such factors
as ion charging in a storage tube.
dynamic demonstrator A teaching aid consisting
of a board displaying an electronic circuit, behind
which is mounted the actual circuit. Various circuit
components (especially adjustable ones) are
mounted on the front of the board, in clear view
at places where their circuit symbols appear. Pin
jacks at important test points in the circuit allow
connection of a meter, signal generator, and oscilloscope
leads for testing or demonstrating the
circuit.
dynamic deviation The difference between ideal
output and actual output of a circuit or device operating
with a reference input that changes at a
constant rate and is free of transients.
dynamic diode tester An instrument that displays
the response curve (or family of curves) of a diode
on a calibrated oscilloscope screen. The horizontal
axis of the screen indicates voltage, the vertical
axis shows current, and zeros for both
quantities are at center screen. Also see DY-
NAMIC RECTIFIER TESTER.
dynamic drain current See AC DRAIN CURRENT.
dynamic drain resistance See AC DRAIN RESIS-
TANCE.
dynamic drain voltage See AC DRAIN VOLTAGE.
dynamic dump A dump that occurs during a program
run. See DUMPING.
dynamic electric field An electric field whose intensity
is constantly changing, either periodically
or in a complex way.
dynamic emitter current See AC EMITTER CUR-
RENT.
dynamic emitter resistance See AC EMITTER
RESISTANCE.
dynamic emitter voltage See AC EMITTER VOL-
TAGE.
dynamic equilibrium 1. The state of balance between
constantly varying quantities. 2. The tendency
of two current-carrying circuits to maintain
at a maximum the magnetic flux linking them.
dynamic error In a periodic signal delivered by a
transducer, an error resulting from the restricted
dynamic response of the device.
dynamic flip-flop A flip-flop (bistable multivibrator)
that is kept on by recirculating an alternating-current
(ac) signal. The device can be
switched on or off by a single pulse. Compare
STATIC FLIP-FLOP.
dynamic focus Compensation for defocusing,
caused by the electron beam sweeping in an arc
across a flat color picture-tube screen; the
method uses an alternating-current (ac) focusing-electrode
voltage.
dynamic gate voltage See AC GATE VOLTAGE.
dynamic impedance The impedance of a device
(such as a transistor or diode) when it is operating
with an applied alternating-current (ac) signal,
as opposed to its static resistance with only
direct current (dc) applied.
dynamic limiter A limiter, such as is used in frequency-modulation
(FM) receivers, that maintains
the output-signal level, despite appreciable
excursions of input-signal amplitude.
dynamic loudspeaker See DYNAMIC SPEAKER.
dynamic magnetic field A magnetic field whose
intensity is constantly changing, either periodically
or in a complex way.
dynamic memory A usually random-access data
storage method in which the memory cells must
be electrically refreshed periodically to avoid the
loss of held data.
dynamic microphone A microphone in which a
small coil attached to a vibrating diaphragm or
cone moves in a uniform magnetic field to generate
the output signal.
Coil
Magnet
Output
Diaphragm
Sound waves
dynamic microphone
dynamic mutual conductance See DYNAMIC
TRANSCONDUCTANCE.
dynamic noise suppressor A noise limiter consisting
of an audio filter whose bandwidth is directly
proportional to signal strength (i.e., it is varied
automatically by signal amplitude).
dynamic operating line A curve displaying the
control function of a device. For example, the
collector-current-versus-base-current curve of a
bipolar transistor is drawn between the limits of
saturation and cutoff.
dynamic output impedance The output impedance
of a power supply, as “seen” by the load.
dynamic pickup A phonograph pickup whose stylus
causes a small coil to vibrate in the field of a
permanent magnet. Works on the same principle
as the DYNAMIC MICROPHONE.
dynamic printout A printout that occurs as a single
function, actuated by one command, and
completing itself in one operation.
dynamic problem checking A method of checking
the solution obtained by an analog computer, to
see that it makes sense (is not absurd).
dynamic programming A method of problem
solving in which continual checks are made to
ensure accuracy or conformance to a certain set
of rules.
dynamic range 1. In high-fidelity audio, the ratio
of the loudest sound to the faintest sound that
can be reproduced without significant distortion