"A"
"B"
"C",
"D",
"E",
"F",
"G",
"H",
"I",
"J",
"K",
"L",
"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
"T" to "Thermio",
"Thermis" to "Top",
"Tor" to "Transf",
"Trans" to "Tre",
"Triac" to "Tub"
"Tun" to "Tz"
TACHOMETER. A small ac or dc generator, sometimes referred to as a rate generator, that converts
its shaft speed into an electrical output. The tachometer is frequently used in servo-systems to sense the velocity of a load. An instrument that measures the rate at which a shaft is turning.
TANK CIRCUIT. A tuned circuit used to temporarily store energy. Also referred to as a parallel-resonant circuit.
TAPPED DELAY LINE. A delay line with multiple tapped outputs so the amount of delay may be selected by choosing another tap or point on the delay line. To change the delay on this type of circuit the output needs to be taken from a different output pin. Related terms, Delay Line, Programmable Delay Line.
Tapped Delay Line
TAPPED RESISTOR. A wire-wound, fixed resistor having one or more additional terminals along its length, generally for voltage-divider applications. Potentiometer Manufacturers.
| Tee CONNECTOR. A style of connector shaped like a 'T'. The connectors may be any gender in any combination. A BNC style Tee is shown to the right, but a Tee connector could be almost any style. More Tee Connector Graphics [BNC, TNC]. Manufacturers of Coax Connectors |
 BNC Tee Connector |
TELECOMMUNICATIONS. The transmission, emission, or reception of signs, signals, writings, images, or sounds. This is done by visual, oral, wire, radio, or other means. The term Telecommunications may also be abbreviated as Telcom.
TEMPERATURE COEFFICIENT. The ratio of the change in a parameter to the change in temperature. The amount of change of resistance in a material per unit change in temperature.
TEMPERATURE INVERSION. The condition in which warm air is formed above a layer of cool air that is near the earth’s surface.
TEMPEST. A term normally used to describe compromising emanations. These emanations are unintentionally radiated signals that could disclose classified information.
| TENTED VIA. A via with dry film solder mask which completely covers both the via pad and its plated-through hole [PTH]. In the example to the right, the via pad and PTH is yellow while the solder mask is off-set in color. Also refer to the definition of Via. Definitions of PWB Terms |
 Tented Via |
TENSILE STRENGTH. The greatest stress a substance can withstand along its length without tearing apart.
TERMINAL. An electrical connection.
TERMINAL BOARD. Also called a terminal strip. An insulating base or slab equipped with terminals for connecting wiring.
TERMINAL DIAGRAM. A diagram of a switch, relay, terminal board, or other component showing the connections to the equipment.
TERMINAL LUG. A device attached to a conductor to permit connection to a terminal. [Terminal Lug Definition]
TEST EQUIPMENT. A general term applied to devices used to test electrical and electronic circuits. [Manufacturers of Test Equipment]
| TEST POINTS. Locations in equipment or devices that are accessible to the technician’s test probes where operating voltages or signals can be monitored. In this example, a Header, but a test point could just be a via or pad on the Printed Wiring Board [PWB]. |
 Test Points |
TETRODE TUBE. A four-electrode electron tube containing a plate, a cathode, a control grid, and a screen grid. [Vacuum Tube]
THERMAL IMPEDANCE. -- . Also refer to 2N3439 Thermal Impedance Graph.
THERMAL INERTIA. The capacity of a soldering iron to generate and maintain a satisfactory soldering temperature while giving up heat to the material being soldered.
THERMAL-MAGNETIC TRIP ELEMENT. A single circuit breaker trip element that combines the action of a thermal and a magnetic trip element.
THERMAL RESISTANCE. the temperature rise, per unit power dissipation, of a junction above the temperature of a stated external reference point under conditions of thermal equilibrium.
THERMAL RUNAWAY. A conduction that exists when heat causes more electron-hole pairs to be generated, which, in turn, causes more heat and which may eventually cause component destruction [in diodes and transistors].
THERMAL TRIP ELEMENT. A circuit breaker trip element that uses the increased bending of a bimetallic strip caused by increased current to open a circuit.
THERMAL VIA. A via in the Printed Wiring Board [PWB] to effectively transfer heat from the top copper layer of the Printed Circuit Board [PCB] to the inner or bottom copper layers. The thermal vias should make their connection to the internal ground plane with a complete connection around the entire circumference of the plated through hole. Do not use a thermal relief web or spoke connection which impedes the conduction path into the inner copper layer. Also refer to the definition of Via, or dictionary of PWB Terms.
THERMIONIC EMISSION. Emission of electrons from a solid body as a result of elevated temperature.
Next set of "T" Terms and definitions
