Three terminal device used to hold the output voltage of
a power supply constant over a wide range of load
Insulated gate field effect transistor. Another name for
(Z) Measured in ohms it is the total opposition to the
flow of current offered by a circuit. Impedance consists
of the vector sum of resistance and reactance.
Coupling of two signal amplifier circuits through the
use of an impedance such as a inductor.
Matching the output impedance of a source to the input
impedance of a load to attain maximum power transfer.
When two or more waves of the same frequency have their
positive and negative peaks occuring at the same time.
State of a material when heated to the point where it
emits light. (red hot or white hot).
Voltage generated in a conductor when subjected to a
moving magnetic field.
Property of a circuit to oppose a change in current. The
moving magnetic field produced by a change in current
causes an induced voltage to oppose the original change.
Circuit having greater inductive reactance than
Opposition to the flow of AC current produced by an
inductor. Measured in Ohms and varies in direct
proportion to frequency.
Length of conductor used to introduce inductance into a
circuit. The conductor is usually wound into a coil to
concentrate the magnetic lines of force and maximize the
inductance. While any conductor has inductance, in
common usage the term inductor usually refers to a coil.
Electromagnetic heat radiation whose frequencies are
above the microwave frequency band and below red in the
To stop an action or block data from passing.
Opposition to the flow of signal current at the input of
a circuit or load.
When a non conducting material is used to isolate
conducting materials from one another.
Material that will prevent the flow of current due to
its chemical composition.
Resistance of insulating material. The greater the
insulation resistance, the better the insulation.
When two or more components are combined into a circuit
and then incorporated into a single package.
A device that approximates and whose output is
proportional to an integral of the input signal. A low
intermediate frequency amplifier
In a superheterodyne radio it amplifies a fixed
frequency lower than the received radio frequency and
higher than the audio frequency.
A fault occuring at random intervals of time.
Intermittent problems are often difficult to locate
because of the random nature. They often don't occur
when the technician is present.
Every source has some resistance in series with the
output current. When current is drawn from the source
some power is lost due to the voltage drop across the
internal resistance. Usually called output impedance or
A semiconductor material with electrical properties
essentially characteristic of ideal pure crystal.
Essentially silicon or germanium crystal with no
intrinsic stand-off ratio
A unijunction transistor (UJT) rating used to determine
the firing potential of the device.
An amplifier that has a 180° phase shift from input to
In an operational amplifier (op amp) the input that is
marked with a minus sign. A signal applied at the
inverting input will be given 180° phase shift between
input and outptu.
An atom with fewer electrons in orbit than the number of
protons in the nucleus is a positive ion. An atom with a
greater number of electrons in orbit than the number of
protons in the nucleus is a negative ion.
Atoms become ionized when they gain or lose a valence