(redirected from transience)
Also found in: Dictionary, Thesaurus, Medical, Legal, Wikipedia.


Physics a brief change in the state of a system, such as a sudden short-lived oscillation in the current flowing through a circuit



(or transient phenomenon). A transient in an electric circuit is a phenomenon that occurs during a transition from one circuit condition to another that differs from the initial condition in the amplitude, phase, shape, or frequency of the voltage acting in the circuit, the values of the parameters, or the configuration of the circuit. Transients occur chiefly when circuit elements are switched into or out of the circuit. The transients arise because the current flowing through an inductance and the voltage across a capacitance cannot be altered abruptly—that is, the energy of the electric and magnetic fields in the circuit’s capacitive and inductive elements cannot be changed instantaneously.

Theoretically speaking, a transient continues for an indefinite period because the voltage and current in an electric circuit after the closing or opening of a switch approach their final (steady-state) values asymptotically. In electrical engineering, however, a transient is considered to be ended when the voltage and current reach values differing from the steady-state values by 5 to 10 percent, a condition that occurs within a comparatively short finite interval of time. An electric circuit that is characterized by constant or periodically varying currents and voltages is said to be in a steady-state condition.

A simple example of a transient is the charging of a capacitor C (Figure 1) from a DC source (a storage battery) having an electromotive force (emf) E and an internal resistance r through a resistor R, which limits the current in the circuit. If the switch is closed at the time t = 0, the current in the circuit decreases according to an exponential law and approaches zero. Simultaneously, the voltage increases and approaches asymptotically the value of the source emf. The rate of change of the voltage and the current depend on the capacitance of the capacitor and the resistance in the circuit: the larger the capacitance and resistance, the longer the duration of the charging process. After a time interval τ = (R + r)C, called the time constant for the charging of the capacitor, the voltage across the capacitor’s plates attains the value uc = 0.6327, and the current i reaches 0.37I0, where I0 is the initial current. I0 is equal to the ratio of the emf and the resistance in the circuit. After a time interval of 5τ;, UC > 0.99E and i < 0.01I0; with an error of less than 1 percent, the transient can be regarded as having ended. During the transient, the energy of the capacitor’s electric field is increased from zero to Wc = CE2/2.

During a transient, in individual parts of a circuit there may occur voltage surges and overcurrents—that is, voltages and currents substantially greater than the steady-state voltages and currents. When equipment is not selected properly, the voltage surges can result in the breakdown of insulation in, for example, capacitors, transformers, and electrical machines. Overcurrents can cause the actuation of protective devices and the disconnection of equipment; they can burn out instruments, burn contacts, and cause mechanical damage to windings as a result of electro-dynamic stresses. Transients play an exceptionally important role in automatic control systems, pulse engineering, computer technology, measurement technology, electronics, radio engineering, and power engineering.


Osnovy teorii tsepei. Moscow-Leningrad, 1965.
Neiman, L. R., and K. S. Demirchian. Teoreticheskie osnovy elektrotekhniki, vol. 1. Leningrad, 1967.
Ginzburg, S. G. Metody resheniia zadach po perekhodnym protsessam ν elektricheskikh tsepiakh, 3rd ed. Moscow, 1967.
Venikov, V. A. Perekhodnye elektromekhanicheskie protsessy ν elektricheskikh sistemakh. Moscow, 1970.
Teoreticheskie osnovy elektrotekhniki, part 1. Moscow, 1972.
Bessonov, L. A. Teoreticheskie osnovy elektrotekhniki. Moscow, 1973.



A pulse, damped oscillation, or other temporary phenomenon occurring in a system prior to reaching a steady-state condition.


1. <electronics> A sudden, brief increase in current or voltage in a circuit that can damage sensitive components and instruments.


A malfunction that occurs at random intervals and lasts for a short duration such as a spike or surge in a power line or a memory cell that intermittently fails. See spike and power surge.
References in periodicals archive ?
A comparison of addiction and transience among street youth: Los Angeles, California, Austin, Texas, and St.
Assuming these risk factors are interrelated and increase risk for illegal behaviors (Baron, 2009), we speculated that length of time homeless will indirectly predict arrest activity, as mediated through transience, substance use disorder, and survival strategies.
BEIRUT: Transience is integral to Beirut's material culture.
If a man fathers a hundred children and lives many years, so that the days of his years are many, but gains no pleasure from his riches, nor proper burial for himself, I say that a stillborn child is better off than he--for in transience it comes [behevel], in oblivion it departs, in the dark a lid is cast over its name.
War and War is only the second Krasznahorkai novel to be translated into English, following The Melancholy of Resistance (also translated by George Szirtes--excellent with everything but cursing and computers--and brought out in America by New Directions six years ago), but even with just this meager evidence to hand, the power and substance of Krasznahorkai's prose, its quality both of familiarity (qua Thomas Bernhard) and fundamental peculiarity (those epic, sinuous, mocking, endlessly associative sentences), is such that his Anglophone readers are bound to feel that he's already a major force--and long established--in our literature: this eras standard-bearer for a tradition of transience, skepticism, and negation.
He said: "The fluidity, changeability of relationships and the transience of marriage may look perfectly fine if you belong to the commentating classes of North London but you don't have to go many miles to see what the cost is for people who cannot take that sort of thing for granted.
THE word ephemeral, from the Greek ephemoros signifying a day's duration, connotes evanescence or transience.
This turn of events started a chain reaction of transience for the Parkinsons.
The question of how one begins to propose a fixed object and fixed image of a project or building alongside such transience is a difficult one," Kushner said.
Ultimately, this is a study of the transience of life and the unavoidable recognition and acceptance of its end.
This book is at its best when it shows how Charley's life and death intersected with larger issues of late nineteenth-century life such as youth, transience, ideals of success, social reform, and frontier politics.
The author's aim is to explore the 'links between transience and the creation of imperial identities .