Difference in time between two
waveforms of the same frequency
expressed in degrees. Example:
One waveform lags another
waveform by a certain number of
degrees.
laminated core
Core made up of sheets of
magnetic material insulated from
one another by an oxide or
varnish.
lamp
Device that produces light.
laser
Device that produces a very
narrow intense beam of light.
The name is an axcronym for
"light amplification by
stimulated emission of
radiation.
lead
The angle by which one
alternating signal leads another
in time. Opposite of lag. Also a
wire that connects two points in
a circuit.
lead-acid cell
Cell made up of lead plates
immersed in a sulphuric acid
electrolyte. An automobile
battery usually consists of six
lead-acid cells.
leakage
Small undesirable flow of
current through an insulator or
dielectric.
LED
Abbreviation for "light emitting
diode."
left-hand-rule
If fingers of the left hand are
placed around a wire so that the
thumb points in the direction of
electron flow, the fingers will
be pointing in the direction of
the magnetic field being
produced by the conductor.
Lenz's law
The current induced in a circuit
due to a change in the magnetic
field is so directed as to
oppose the flux, or to exert a
mechanical force to oppose the
motion.
level detector
An op-amp circuit that compares
two inputs and provides a DC
output indicating the polarity
relationship between the inputs.
A comparitor.
lie detector
Piece of electronic equipment
also called a polygraph used to
determine whether a person is
telling the truth by looking for
dramatic changes in blood
pressure, body temperature,
breathing rate, heart rate and
skin moisture in response to
questions.
light
Electromagnetic radiation in a
band of frequencies that can be
received by the human eye.
lifetime
The time from the creation of an
electron hole pair until
recombination occurs.
light-emitting diode
A semiconductor diode that
converts electric energy into
electromagnetic radiation at a
visible and near infrared
frequencies when its pn
junction is forward biased.
limiter
Circuit or device that prevents
some portion of its input from
reaching the output. A clipper.
linear
Relationship between input and
output in which the output
varies in direct proportion to
the input.
linear scale
A scale in which the divisions
are uniformly spaced.
line regulation
The ability of a voltage
regulator to maintain a constant
voltage when the regulator input
voltage varies.
live
Term used to describe a circuit
or piece of equipment that is on
and has current flow within it.
load
A source drives a load. Whatever
component or piece of equipment
is connected to a source and
draws current from a source is a
load on that source.
load current
Current drawn from a source by a
load.
load impedance
Vector sum of reactance and
resistance in a load.
loading effect
Large load impedance will draw a
small load current and so
loading of the source is small.
(light load). A small load
impedance will draw a large load
current from the source. (heavy
load).
load regulation
The ability of a voltage
regulator to maintain a constant
output voltage under varying
load currents.
load resistance
Resistance of a load.
logic
Science of dealing with the
principle and applications of
gates, relays and switches.
loss
Term used to describe a decrease
in power.
low pass filter
A tuned circuit designed to pass
all frequencies below a
designated cut-off frequency.
