Condition in which a further increase in one variable
produces no further increase in the resultant effect. In
a bipolar junction transistor, the condition when the
emitter to collector voltage is less than the emitter to
base voltage. This condition puts forward bias on the
base to collector junction.
Repeating waveform that rises from zero to maximum value
linearly drops back to zero and repeats. A ramp
Set of markings used for measurement.
Illustration of an electrical or electronic circuit with
the components represented by their symbols.
Circuit to convert a given waveform to a square wave
High speed diode that has very little junction
capacitance. Also known as a "hot-carrier diode" or a
Numbers entered as a number from one to ten multiplied
by a power of ten. Example: 8765 = 8.765 × 103.
Output winding of a transformer. Winding that is
connected to a load.
Electrolytic cell used to store electricity. Once
discharged may be restored by recharging by putting
current through the cell in the direction opposite to
that of discharge current.
Charistic of a circuit to discriminate between wanted
and unwanted signals.
Gate bias for a field effect transistor in which source
current through a resistor produces the voltage for gate
to source bias.
Property that causes a counterelectromotive force to be
produced in a conductor when the magnetic field expands
or collapses with a change of current.
An element which is neither a good conductor or a good
insulator, but rather lies somewhere between the two.
Characterized by a valence shell containing four
electrons. Silicon, germanium and carbon are the
semiconductors most frequently used in electronics.
Circuit in which the components are connected end to end
so that current has only one path to follow through the
series parallel network
Network that contains components connected in both
series and parallel.
Condition that occurs in a series LC circuit at the
frequency where inductive reactance equals capacitive
reactance. Impedance is minmum, current is maximum
limited only by resistance in the circuit.
seven segment display
Device made of several light emitting diodes arranged in
a numeric or alphanumeric pattern. By lighting selected
segments numeric or alphabet characters can be
shells or bands
Orbital path containing a group of electrons having a
common energy level.
Metal grounded cover used to protect a wire, component
or piece of equipment from stray magnetic and/or
Also called a short. Low resistance conection between
two points in a circuit typically causing excessive
Resistor connected in parallel or in shunt with another
component or circuit.
Electrical quantity that conveys information.
signal to noise ratio
Ratio of the magnitude of the signal to the magnitude of
noise usually expressed in decibels.
(Si) Non metalic element (atomic number 14) used in pure
form as a semiconductor.
silicon controlled switch
An SCR with an added terminal called an anode gate. A
positive pulse either at the anode gate or the cathode
gate will turn the device on.
Glass like material used as the gate insulating material
in a MOSFET.
A bipolar junction transistor using silicon as the
(SCR) Three terminal active device that acts as a gated
diode. The gate terminal is used to turn the device on
allowing current to pass from cathode to anode.
(Ag) Precious metal that does not easily corrode and is
more conductive than copper.
silver mica capacitor
Mica capacitor with silver deposited directly onto the
mica sheets instead of using conductive metal foil.
Solder composed of silver, copper and zinc. Has a
melting point lower than pure silver, but higher than
Communication in only one direction at a time. Example:
Broadcasting a program simultaneously in two different
forms, for example a program broadcast in both AM and
Sine of an angle of a right angle triangle is equal to
the opposite side divided by the hypotenuse.
Wave whose amplitude is the sine of a linear function of
time. It is plotted on a graph that plots amplitude
against time or radial degrees relative to the angular
rotation of an alternator.
single in-line package
Package containing several electronic components
(generally resistors) with a single row of connecting
single pole double throw
(SPDT) Three terminal switch in which one terminal can
be connected to either one of the other terminals.
single pole single throw
(SPST) Two terminal switch or relay thet can open or
close one circuit.
(SSB) AM radio communication technique in which the
transmitter suppresses one sideband and therefore
transmits only a single sideband.
single throw switch
Switch containing only one set of contacts which can be
either opened or closed.
Device such as a load that consumes power or conducts
Process of bonding either a metal or powder by cold
pressing it into a desired shape and then heating to
form a strong cohesive body.
Varying in proportion to the sine of an angle or time
function. AC voltage in which the instantaneous value is
equal to the sine of the phase angle times the peak
Abbreviation for "single in-line package."
Tendancy of high-frequency (rf) currents to flow near
the surface layer of a conductor.
The maximum rate at which the output voltage of an
op-amp can change.
Switch having a sliding button, bar or knob.
slow acting relay
Slow operating relay that when energized may not pull up
the armature for several seconds.
Fust that can withstand a heavy current (up to ten times
its rated value) for a small period of time before it
Switch containing a spring under tension or compression
that causes the contacts to come together suddenly when
Abbreviation for "signal to noise ratio."
soft magnetic material
Ferromagnetic material that is easily demagnetized.
Program of instructions that directs the operation of a
Photovoltaic cell that converts light into electric
energy. Especially useful as a power source for space
Metallic alloy used to join two metal surfaces.
Process of joining two metallic surfaces to make an
electrical contact by melting solder (usually tin and
lead) across them.
Tool with an internal heating element used to heat
surfaces being soldered to the point where the solder
An air core coil. Equipped with a movable iron core the
solenoid will produce motion. As a result of current
through the coil the iron core is pulled into the center
of the winding. When the coil is deenergized, a spring
pulls the movable core away from the center of the
winding. Machanical devices connected to the movable
core are made to move as a result of current through the
coil. Example: Electric door locks on some automobiles.
Conductor having a single solid wire instead of strands
of fine wire twisted together.
Pertaining to circuits where signals pass through solid
semiconductor material such as transistors and diodes as
opposed to vacuum tubes where signals pass through a
Acronym for "sound navigation and ranging." A system
using reflected sound waves to determine the position of
Pertaining to sound.
Pressure waves propagated through air or other plastic
media. Sound waves are generally audible to the human
ear if the frequency is between approximately 20 and
20,000 vibrations per second. (hertz)
Device that provides signal power or energy to a load.
FET amplifier in which signal is applied between gate
and drain with output taken between source and drain.
Also called "common drain."
Impedance through which output current is taken from a
Pole of a magnet into which magnetic lines of force are
assumed to enter.
Momentary discharge of electrical energy due to
ionization of air or other dialectric material
separating two charges.
Single pole double throw.
Also called "loudspeaker." Transducer that converts
electrical energy into mechanical energy at audio
Arrangement or display of light or other forms of
electromagnetic radiation separated according to
wavelength, energy or some other property.
Instrument used to display the frequency domain of a
waveform plotting amplitude against frequency.
Capacitor added to the base circuit of a BJT switching
circuit to improve the switching time of the device.
Abbreviation for "single pole single throw."
Wave that alternates between two fixed values for an
equal amount of time.
Crackling noise heard on AM radio receivers. Caused by
electric storms or electric devices.
Stationary electric charges.
static reverse current
Reverse current through a zener diode when the reverse
voltage across the diode is less than the zener voltage
rating of the device.
Stationary part of some rotary device such as a variable
Transformer in which the output AC voltage is less than
the input AC voltage.
Transformer in which the output AC voltage is greater
than the input AC voltage.
System in which reproduced sound is delivered through
two or more channels to give a sense of direction to the
Range of frequencies outside the pass band of a tuned
In a BJT switching circuit, it is the time required for
collector current to drop from 100% to 90% of its
Conductor composed of a group of strands of wire twisted
Undesirable capacitance that exists between two
conductors such as two leads or one lead and a metal
Components contained in a unit for convenience in
assembling or servicing equipment.
Particles such as electrons, protons and neutrons that
are smaller than atoms.
Mechanical insulating support upon which a device is
An op-amp circuit whose output is proportional to the
sum of its instantaneous voltages.
super high frequency
(SHF) Frequency band between 3 GHz and 30 GHz. So
desiganted by Federal Communications Comission (FCC).
Metal such as lead or niobium that, when cooled to
within a few degrees of absolute zero, can conduct
current with no resistance.
Radio receiver that converts all radio frequencies to a
fixed intermediate frequency to maximize gain and
bandwidth before demodulation.
Theorem designed to simplify networks containing two or
more sources. It states that in a network containing
more than one source, the current at any one point is
equal to the algebraic sum of the currents produced by
each source acting separately.
Voltage provided by a power source.
surface leakage current
Diode reverse current that passes along the surface of
the semiconductor materials.
(Schottky diode)High speed diode that has very little
junction capacitance. Also known as a "hot-carrier
High charging current that flows into a power supply
filter capacitor as the power is first turned on.
Test instrument designed to produce a voltage that
continously varies in frequency over a band of
frequencies. Used as a souce to display frequency
response of a circuit on an oscilloscope.
Electrical device having two states, on (closed) or off
(open). Ideally having zero impedance when closed and
infinite impedance when open.
transistor designed to change rapidly between saturation
Pulse used as a reference for synchronization.
Also called sync. Precise matching of two waves or
Two or more signals in step or in phase.
Combination of several pieces of equipment to perform in
a particular manner.