Page 97 - Electrical Engineering Dictionary

evaporates the feedwater and generates high- Boolean an operator or an expression of
pressure steam. George Boole’s algebra (1847). A Boolean
variable or signal can assume only two val-
boiling water reactor a nuclear reactor ues: TRUE or FALSE. This concept has been
from which heat is transferred in the form of ported in the field of electronic circuits by
high-pressure steam. Claude Shannon (1938). He had the idea to
use the Boole’s algebra for coding the status
bolted fault a bolted fault is a short cir- of circuit: TRUE/FALSE as HIGH/LOW as
cuit fault with no fault resistance. Bolted CLOSE/OPEN, etc.
faults deliver the highest possible fault cur-
rent for a given location and system config- Booleanalgebra thefundamentalalgebra
at the basis of all computer operations. See
uration, and are used in selecting equipment
withstand and interrupting ratings and in the also the other definitions with Boolean as the
setting of protective relays. first word.

Boolean expression an expression of
Boltzmann machine in its simplest form,
the Boole’s algebra, in which can appear
a discrete time Hopfield network that em-
Boolean variables/signals and Boolean oper-
ploys stochastic neurons and simulated an-
ators. Boolean expressions are used for de-
nealing in its procedure for updating output
scribing the behavior of digital equipments
values. More generally it can have hidden
or stating properties/conditions in programs.
units and be subjected to supervised training
so as to learn probabilities of different out-
Boolean function common designation
puts for each class of inputs.
for a binary function of binary variables.
Boltzmann relation relates the density
Boolean logic the set of rules for logical
of particles in one region to that in an ad-
operations on binary numbers.
jacent region, with the potential energy be-
tween both regions.
Boolean operator the classical Boolean
operators are AND, OR, NOT. Other oper-
bond that which binds two atoms to-
ators such as XOR, NAND, NOR, etc., can
gether.
be easily obtained based on the fundamen-
tal ones. In hardware these are implemented
bond pad areas of metallization on the IC with gates, see for example AND gate.
die that permit the connection of fine wires
or circuit elements to the die. boost converter a circuit configuration in
which a transistor is switched by PWM trig-
bonded magnet a type of magnet ger pulses and a diode provides an inductor-
consisting of powdered permanent magnet current continuation path when the transistor
material, usually isotropic ceramic ferrite is off. During the transistor on-time, the cur-
or neodymium-iron-boron, and a polymer rent builds up in the inductor. During the
binder, typically rubber or epoxy, this magnet transistor off-time, the voltage across the in-
material can be molded into complex shapes. ductor reverses and adds to the input voltage,
as a result, the output voltage is greater than
bonding the practice of ensuring a low- the input voltage.
resistance path between metallic structures A boost converter can be viewed as a
such as water lines, building frames, and ca- reversed buck converter. The output volt-
ble armor for the purpose of preventing light- age v o is related to the input voltage v i by
ning arcs between them. v o = v i /(1 − d) and it can be controlled by

c
2000 by CRC Press LLC