Transient (oscillation)

# Transient (oscillation)

Discussion

Encyclopedia
A transient event is a short-lived burst of energy in a system caused by a sudden change of state.

The source of the transient energy may be an internal event or a nearby event. The energy then couples to other parts of the system, typically appearing as a short burst of oscillation.

## Electrical Engineering

In electrical engineering, oscillation is an effect caused by a transient response
Transient response
In electrical engineering and mechanical engineering, a transient response or natural response is the response of a system to a change from equilibrium. The transient response is not necessarily tied to "on/off" events but to any event that affects the equilibrium of the system...

of a circuit or system. It is a momentary event preceding the steady state (electronics)
In electronics, steady state is an equilibrium condition of a circuit or network that occurs as the effects of transients are no longer important....

during a sudden change of a circuit.

Mathematically, it can be modeled as a damped harmonic oscillator.

An example of transient oscillation can be found in digital (pulse) signals in computer networks. Each pulse produces two transients, an oscillation resulting from the sudden rise in voltage and another oscillation from the sudden drop in voltage. This is generally considered an undesirable effect as it introduces variations in the high and low voltages of a signal, causing instability.

## Electromagnetics

In electrical
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...

and electronic engineering
Electronic engineering
Electronics engineering, also referred to as electronic engineering, is an engineering discipline where non-linear and active electrical components such as electron tubes, and semiconductor devices, especially transistors, diodes and integrated circuits, are utilized to design electronic...

such electromagnetic pulses (EMP) occur internally as the result of the operation of switching devices. Engineers use voltage regulator
Voltage regulator
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components...

s and surge protector
Surge protector
A surge protector is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold...

s to prevent transients in electricity from affecting delicate equipment. External sources include lightning (LEMP), electrostatic discharge (ESD) and nuclear EMP (NEMP).

Within Electromagnetic compatibility
Electromagnetic compatibility
Electromagnetic compatibility is the branch of electrical sciences which studies the unintentional generation, propagation and reception of electromagnetic energy with reference to the unwanted effects that such energy may induce...

testing, transients are deliberately administered to electronic equipment for testing their performance and resilience to transient interference. Many such tests administer the induced fast transient oscillation directly, in the form of a damped sine wave, rather than attempt to reproduce the original source. International standards define the magnitude and methods used to apply them.

The European standard for Electrical Fast Transient (EFT) testing is EN-61000-4-4. The U.S. equivalent is IEEE C37.90. Both of these standards are similar. Which standard you choose is based on the intended market.

## Acoustics

The typical sound of some musical instrument
Musical instrument
A musical instrument is a device created or adapted for the purpose of making musical sounds. In principle, any object that produces sound can serve as a musical instrumentâ€”it is through purpose that the object becomes a musical instrument. The history of musical instruments dates back to the...

s is also characterized by transients, which can be heard when striking a percussion instrument
Percussion instrument
A percussion instrument is any object which produces a sound when hit with an implement or when it is shaken, rubbed, scraped, or otherwise acted upon in a way that sets the object into vibration...

or the strings of a string instrument
String instrument
A string instrument is a musical instrument that produces sound by means of vibrating strings. In the Hornbostel-Sachs scheme of musical instrument classification, used in organology, they are called chordophones...

.