18WuD2x

unblanking pulse • unconditional jump 705
unblanking pulse A pulse that turns on the beam
of a blanked cathode-ray tube. Compare BLANK-
ING PULSE.
unblanking time 1. See UNBLANKING INTERVAL.
2. The instant at which unblanking begins.
unbonded strain gauge A strain gauge that is not
directly attached (by cement, for example) to the
strained surface.
unbound electron A free electron (i.e., an electron
not confined to a shell within an atom).
unbuffered output An output (signal, power, etc.)
that is delivered directly from the generating device
without the benefit of an isolating stage,
such as a buffer amplifier. Compare BUFFERED
OUTPUT.
unbypassed emitter resistor In a common-emitter
transistor circuit, an emitter resistor without
a bypass capacitor. The flow of output-signal current
through the resistor produces negative feedback
within a single stage.
Input
R C
−V CC
C I
R B R E
C O
Output
unbypassed emitter resistor (R E )
unbypassed source resistor In a common-source
field-effect transistor circuit, a source resistor
without a bypass capacitor. The flow of outputsignal
current through the resistor produces negative
feedback within a single stage.
uncage In a displacement gyroscope system, to
disconnect the erection circuit.
uncalibrated unit A component, circuit, or instrument
that has never been calibrated or has not
recently been calibrated and, hence, is of questionable
accuracy.
uncanny valley According to a theory put forth by
certain Japanese roboticists, a phenomenon that
can occur among people as technology advances.
As machines rapidly get more sophisticated, a
point is reached at which their human users become
unnerved, partially offsetting the advantages
the technology has to offer.
uncased choke See UNSHIELDED CHOKE.
uncased transformer See UNSHIELDED TRANS-
FORMER.
uncertainty in computation The degree of doubt
concerning the exactness of computations. This
uncertainty is always greater than that of the
roughest measurement used in obtaining data for
the computation. Uncertainty is closely related to
the tolerance of the instruments and formulas
used.
uncertainty in measurement The estimated maximum
amount whereby the numerical value of a
measured quantity can differ from the true value.
uncertainty principle The observation that high
precision in the location of an electron is obtainable
only at a sacrifice in the accuracy with which
the momentum of the electron can be determined,
and vice versa.
uncharged Without an electric charge, as opposed
to discharged (depleted of a charge).
unclamp To switch off clamping action in a circuit.
See CLAMPER and CLAMPING.
uncoated filament 1. A plain filament (i.e., one
without a coating of electron-increasing material).
2. A stripped filament (i.e., one from which the
electron-increasing coating has been burned off).
uncompensated Not modified to produce a desired
type of performance, such as increased bandwidth
or reduced temperature sensitivity. Example:
an uncompensated amplifier put into service
in the (wide) video band. Compare COMPEN-
SATED AMPLIFIER, COMPENSATED CAPACI-
TOR, and COMPENSATED DIODE DETECTOR.
uncompensated amplifier An amplifier without a
provision for the automatic or manual modification
or correction of its response. Compare COM-
PENSATED AMPLIFIER.
uncompensated capacitor A fixed or variable capacitor
without a provision for the automatic or
manual correction or modification of its capacitance
or range or the improvement of its temperature
coefficient. Compare COMPENSATED
CAPACITOR.
uncompensated inductor A fixed or variable inductor
without a provision for the automatic or
manual correction or modification of its inductance
or range or the improvement of its temperature
coefficient.
uncompensated resistor A fixed or variable resistor
without a provision for the automatic or manual
correction or modification of its resistance or
range or the improvement of its temperature coefficient.
unconditional branch See UNCONDITIONAL
JUMP.
unconditional jump In computer operations, a program
instruction that interrupts, without a relational
test being made, the normal, ordered
sequence of instructions and gives the address of
(usually) the first instruction in a subroutine [e.g.,
BASIC’s GOTO (line number)]. Also called unconditional
branch. Compare CONDITIONAL JUMP.