Electronic Engineering Dictionary

Transient. A sudden change in circuit conditions of short duration [but lasting longer than a Spike]. A short-lived increase or decrease in line voltage, see Voltage Transient. A voltage surge.

Transient Response. [TR] The closed-loop step function response of an amplifier under small-signal conditions. A step-function response. The system response to a unit impulse.

Transient Voltage Suppressor. [TVS] A semiconductor device designed to absorb a transient over-voltage. The device may be designed as Uni-Polar device protecting in one direction or a Bi-Polar device protecting the circuit in both directions. Refer to Transient Voltage Suppressor manufacturers.

Transistor. A semiconductor device with three or more elements, Emitter, Base, and Collector and capable of providing power amplification. Also called a Bi-Polar Junction Transistor [BJT]. [Transistor Terms, BJT Manufacturers]

BJT

Transistor Transistor Logic. [TTL] A family of digital logic integrated circuits with a number of sub-families. The base IC is the 7400 NAND gate. The inputs to a TTL gate is usually through a multi-emitter transistor. While the output is taken from a push-pull or totem-pole stage. A two-input AND gate is shown in the right side-bar. Read more on Transistor Transistor Logic.

Transition. The time it take for a signal to change from one logic level to another. The time it takes to shift from a mark to a space condition or from a space to a mark condition. In a signal, the changing from one significant condition to another.

Transit Time. The time an electron takes to cross the distance between the cathode and the plate.

Translation. In a gyro, a force acting through the center of gravity of the gyro that causes no torque on the gyro rotor. Translation forces do not change the angle of the plane of rotation but move the gyroscope as a unit.

Translator. A device that converts information from one system of representation into equivalent information in another system of representation.

Translucent. Those substances through which some light rays can pass but through which objects cannot be seen clearly.

Transmission Control Protocol. A network protocol that controls host-to-host transmissions over packet switched communication networks.

Transmission Frame. A data structure, beginning and ending with delimiters, that consists of fields predetermined by a protocol for the transmission of user data and control data.

Transmission Line. A device designed to guide electrical or electromagnetic energy from one point to another. A line used to transmit high-voltage electricity from the generation source or substation to another substation in the electric distribution system. The material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electric currents, magnetic fields, acoustic waves, or electromagnetic waves.

Transmission Loss. The decrease in power that occurs during transmission from one point to another.

Transmission Medium. A means of transferring intelligence from point to point; includes light, smoke, sound, wire lines, and radio-frequency waves.

Transmit-Receive Tube. [TR] A gas-filled RF switch that is used as a duplexer.

Transmittance. The ratio of the transmitted power to the incident power.

Transmitter. Equipment that generates and amplifies an RF carrier, modulates the RF carrier with intelligence, and radiates the signal into space.

Transmitter End. Same as Input End.

Transmitter Frequency. [Carrier Frequency] The frequency of the unmodulated output of a transmitter.

Transmitter Transfer Switchboard. Equipment that selectively transfers remote station functions and signals to transmitters.

Transparent. Those substances, such as glass, that pass almost all of the light waves falling upon them.

Transponder. An automatic device that receives, amplifies, and retransmits a signal on a different frequency.

Transposition. In data transmission, a transmission defect in which, during one character period, one or more signal elements are changed from one significant condition to the other, and an equal number of elements are changed in the opposite sense.

Transverse Electric Mode. [TE] A mode whose electric field vector is normal to the direction of propagation. A waveguide mode in which the entire electric field is perpendicular to the wide dimension and the magnetic field is parallel to the length. Also called the TE mode. Companies making Waveguide

Transverse Magnetic Mode. [TM] A mode whose magnetic field vector is normal to the direction of propagation. A waveguide mode in which the entire magnetic field is perpendicular to the wide dimension and some portion of the electric field is parallel to the length. Also called the TM mode.

Transverse Wave Motion. The up and down motion of a wave as the wave moves outward.

Trapezoidal Waveform. A shape of a waveform, in many cases periodic waveform. A trapezoidal signal has an initial jump in voltage, followed by a linear rise in voltage to a final peak value, than an instantaneous decrease in voltage back to the initial point. A periodic waveform would have some defined quiet time before the waveform repeated. As with any waveform, the voltage steps are not defined. The companion site shows the Trapezoid wave shape and a Transistor Trapezoid Signal Generator.

Tray. A Cable Tray used to hold and carry wires. A utility tray or Equipment Shelf used as a work area. A container used to ship components in.

Treble Control. A passive circuit used to attenuate frequencies in the lower audio ranges, allowing frequencies in the higher 'treble' range to pass un-attenuated. Refer to Treble Control Schematic.

Tree Structure. A hierarchical organization in which a given node is considered to be an ancestor of all the lower level nodes to which the given node is connected. Read more on Network Structures.

Tremendously High frequency. [THF] The band of frequencies from 300 gigahertz to 3,000 gigahertz.

Tremolo. Amplitude modulation of a signal by a low frequency oscillator.