18WuD2x

82 booster battery • bow-tie test
booster battery 1. A battery used to forward bias a
diode detector into a favorable region of its conduction
curve, or to bias a bolometer into the
square-law region of its response. 2. A battery
supplying power to a booster.
booster gain The amplification (usually in terms of
voltage gain) provided by a booster (see especially
BOOSTER, 2).
boot 1. The powering-up routine in a digital computer,
in which the machine executes a series of
programs to get itself ready for use. 2. The
resetting of a computer, by pressing certain keyboard
keys (e.g., CTRL-ALT-DEL), pressing a reset
button, or by powering-down, waiting about
two minutes, and then powering-up again. 3. To
install a computer diskette and instruct the computer
to execute one or more programs on the
diskette. 4. A usually flexible protective nipple or
jacket pulled over a cable or connector, so called
from its resemblance to a foot boot.
boot loader A form of computer program that operates
on the BOOTSTRAP ROUTINE.
bootstrap A technique for making a device or process
achieve a condition through its own actions;
see BOOTSTRAP CIRCUIT, for example.
bootstrap circuit A specialized form of follower
circuit that presents very high input impedance.
Its chief feature is the return of the control-element
resistor to a tap on the source or emitter resistor.
The technique takes its name from the
figurative notion that such a circuit “lifts its input
impedance by its own bootstraps.”
Signal input
C1
R1
Vdc
+ −
R2
R3
C2
Signal output
bootstrap circuit
(with junction-type field-effect transistor)
bootstrap routine 1. Also called bootstrap program.
In a digital computer, and especially in a
personal computer, the routine that the machine
follows when first powered-up. See BOOT, 1.
2. In a digital computer, a routine in which the first
few instructions put in storage are later used to
complete the routine, as supplemented by some
operator instruction. 3. A portion of a computer
program that is used to establish an alternate
version of the program.
borax-aluminum cell An electrolytic cell that consists
essentially of an aluminum electrode and a
lead electrode in a saturated solution of sodium
tetraborate (borax). After electroforming, such a
cell can be used either as a rectifier or as an electrolytic
capacitor.
boric acid Formula, H 3 BO 3 . A compound used variously
in electronics—especially as the electrolyte
in electrolytic capacitors.
bornite Formula, Cu 5 FeS 4 . A natural mineral that
is a sulfide of copper and iron. Its crystalline
structure made it important in early semiconductor
diodes (crystal detectors).
boron Symbol, B. A metalloidal element. Atomic
number, 5. Atomic weight, 10.82. It is used as a
dopant in semiconductor processing.
bot 1. Abbreviation for beginning of tape. 2. Abbreviation
of bottom.
bottoming Excessive movement of the cone of a
loudspeaker or the diaphragm of a headphone so
that the magnet or supporting structure is struck
by the moving-coil piston assembly. It produces a
clapping sound, particularly on bass (lowfrequency)
audio peaks.
bounce 1. The springback or vibration of the armature
of a relay on closure. 2. An abnormal,
abrupt change in the brightness of the image in a
television receiver or cathode-ray-tube (CRT)
computer monitor.
boundary 1. In a polycrystalline substance, the
area of contact between adjacent crystals. 2. The
area of meeting of two regions (such as n and p)
in a semiconductor.
boundary defect A condition in which a piezoelectric
crystal has two regions, intersecting in a
plane, with different polarizations.
boundary effect In audio systems, a pheno-menon
in which the proximity of an acoustic transducer
to a flat surface enhances the pickup and/or
transmission of sound. Occurs because of reflection
of acoustic waves from the surface.
bound charge The portion of the electric charge on
a conductor that does not escape to ground when
the conductor is grounded. This occurs because
of induction from neighboring charge carriers.
Compare FREE CHARGE.
bound electron An electron held tightly in its orbit
within an atom so that it is not ordinarily free to
drift between atoms and contribute to electric
current flow.
bow-tie antenna A center-fed antenna in which
the two horizontal halves of the radiator are triangular
plates that resemble a bow tie. A flat reflector
consisting of closely spaced horizontal
wires is mounted behind the triangles.
bow-tie test An oscilloscope-display checkout of a
single-sideband (SSB) signal, in which the appearance
of the display indicates the signal quality.
The transmitter output signal is fed to the