The term delay line has multiple meanings:

• In electronics and derivative fields such as telecommunications, a delay line is rigorously defined as a single-input-channel device, in which the output channel state at a given instant, t, is the same as the input channel state at the instant t−n, where n is a number of time units, i.e., the input sequence undergoes a delay of n time units, such as n femtoseconds, nanoseconds, or microseconds. (The delay line may have additional taps yielding output channels with values less than n.) In other words, the device introduces a delay of a certain amount of time between its input and output. Specific devices and approaches:
  • A transmission line or equivalent device (such as an analog delay line) used to delay a signal.
  • In computer simulation it can be used as a numerical technique, also called bi-directional delay line or transmission line modelling (TLM) method.
  • In digital logic and digital signal processing, a delay line refers to a sequential logic element in which the output state at a given time n (in samples) is the same as the input was at the time n−L. Delay lines are generally expressed as z^-L, where L is the length of the delay in samples. A unit delay (a delay of one sample) is therefore expressed as z^-1.
  • In computing, delay line often refers to delay line memory.
• In neurobiology, delay lines can refer to neurons, the cells that transmit electrical information in the brain. Electrical conduction in neurons is not instantaneous; it is delayed depending on the length of the axon and other properties of the neuron (e.g. myelination). This delay can be used for time sensitive calculations; the canonical example is the calculation of inter-aural time differences in the pons, used for sound localization.

An earlier version of this page came from Federal Standard 1037C and from MIL-STD-188. Two digital voltmeters The field of electronics is the study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles in devices such as thermionic valves and semiconductors. ... Telecommunication is the extension of communication over a distance. ... Information processing In information processing, input is the process of receiving information from an object. ... For the geographical meanings of this word, see channel (geography). ... Information processing In information processing, output is the process of transmitting information (verb usage). ... 8:17 am, August 6, 1945, Japanese time. ... This is a page about mathematics. ... Delay is: In sound effects, any of a class of effect that adds one or more delayed versions of the original signal, to create effects such as echo or flanger. ... A femtosecond is the SI unit of time equal to 10-15 of a second. ... A nanosecond is an SI derived unit of time equal to 10-9 of a second. ... A microsecond is an SI unit of time equal to one millionth (10-6) of a second. ... Delay is: In sound effects, any of a class of effect that adds one or more delayed versions of the original signal, to create effects such as echo or flanger. ... A transmission line is 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 electromagnetic waves or acoustic waves. ... A signal may refer to: an abstract element of information, or, more exactly, usually a flow of information (in either one or several dimensions). ... A computer simulation or a computer model is a computer program which attempts to simulate an abstract model of a particular system. ... Bi-directional delay line is a numerical technique used in computer simulation for solving ordinary differential equations by converting them to hyperbolic equations. ... Digital circuits are electric circuits based on a number of discrete voltage levels. ... Digital signal processing (DSP) is the study of signals in a digital representation and the processing methods of these signals. ... Originally, the word computing was synonymous with counting and calculating, and a computer was a person who computes. ... Delay line memory was a form of computer memory used on some of the earliest digital computers, such as the EDSAC and UNIVAC I. The first such systems consisted of a column of mercury with piezo crystal transducers (a combination of speaker and microphone) at either end. ... Neurons (also spelled neurones or called nerve cells) are the primary cells of the nervous system. ... In the anatomy of animals, the brain, or encephalon, is the supervisory center of the nervous system. ... An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, which conducts electrical impulses away from the neurons cell body or soma. ... In neuroscience, myelin is an electrically insulating fatty layer that surrounds the axons of many neurons, especially those in the peripheral nervous system. ... The pons is a knob on the brain stem. ... Sound localization is a listeners ability to identify the location of origin of a detected sound or the methods in acoustical engineering to simulate the placement of an auditory cue in a virtual 3D space (see binaural recording). ... Federal Standard 1037C entitled Telecommunications: Glossary of Telecommunication Terms is a U.S. Federal Standard, issued by the General Services Administration pursuant to the Federal Property and Administrative Services Act of 1949, as amended. ... MIL-STD-188 is a series of U.S. military standards relating to telecommunications. ...