time constant

American  

noun

Electricity.

1. the time required for a changing quantity in a circuit, as voltage or current, to rise or fall approximately 0.632 of the difference between its old and new value after an impulse has been applied that induces such a change: equal in seconds to the inductance of the circuit in henries divided by its resistance in ohms.

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time constant British  

noun

1. electronics the time required for the current or voltage in a circuit to rise or fall exponentially through approximately 63 per cent of its amplitude

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Etymology

Origin of time constant

First recorded in 1890–95

Example Sentences

“Our results suggest that the optimal tempo for beat synchronization depends on the time constant in the brain,” Dr. Takahashi said.

From Washington Times • Nov. 13, 2022

Nor is time constant, despite what the existence of an international standard might suggest.

From Seattle Times • Apr. 25, 2022

The voltage decreases exponentially, falling a fixed fraction of the way to zero in each subsequent time constant τ .

From Textbooks • Aug. 12, 2015

He once used Twitter to find out the relaxation time constant for ocean acidification as a result of a carbon dioxide perturbation, an obscure topic not well-attuned to a simple Google search.

From Nature • Mar. 30, 2011

Under these circumstances the time constant of the instrument on short circuit is 0.0081 sec.

From Scientific American Supplement, No. 787, January 31, 1891 by Various