Talk:Time constant: Difference between revisions
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For a reference take a look at Purves et al. Chapter three Box C |
For a reference take a look at Purves et al. Chapter three Box C |
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--[[User:Dylan2106|Dylan2106]] ([[User talk:Dylan2106|talk]]) 23:45, 18 March 2008 (UTC) |
--[[User:Dylan2106|Dylan2106]] ([[User talk:Dylan2106|talk]]) 23:45, 18 March 2008 (UTC) |
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:The passive membrane properties of a cell are modeled by a simple RC circuit, hence why tau = RC--[[User:Dylan2106|Dylan2106]] ([[User talk:Dylan2106|talk]]) 23:47, 18 March 2008 (UTC) |
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Revision as of 23:47, 18 March 2008
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Moved initial content to RC time constant because it was too specific. Added temporary redirect but eventually the time constant of a first-order linear system should be discussed here.
Time constant in a two-phase asynchronous motor model
J = moment of inertia
f = rotational friction coefficient
Two stator coils with each nst sinusoidal distributed windings
Two rotor coils with each nrot sinusoidal distributed windings
The angle between the coils is 90 degrees.
Two voltage sources applied on the stator, the angle between the voltages
is 90 degrees.
Ust = effective value of each stator voltage
fst = stator frequency
ωst = 2πfst = angular stator frequency
Two external rotor resistances, each Rrot
Time constant = J/(f+2(Ust/ωst)^2/Rrot')
with Rrot'= Rrot(nst/nrot)^2
Starting from zero the motor speed remains constant after a time 5*(time constant).
Martin Segers (talk) 08:20, 5 January 2008 (UTC)
Thermal transfer section
- Please, include the corresponding units.
- Please, correct references as to allow all users to acces them.
- Please, include the permafrost reference.
The time constant for heat applied at the surface of an insulating body with thermal diffusivity κ to penetrate a distance L can be expressed thus:
This equation can be used to determine, for example, the thickness of the active permafrost layer (where κ ~ 10-6), or how long it takes to boil an egg.[1][2]
Time constant in electrophysiology
I believe that the statement that the exponential functions describe the rise and fall of the action potential is false. I was under the impression that those particular expressions describe only the response of an ideal specially uniform cell without any voltage gated ion channels to a current injection. For a reference take a look at Purves et al. Chapter three Box C --Dylan2106 (talk) 23:45, 18 March 2008 (UTC)
- The passive membrane properties of a cell are modeled by a simple RC circuit, hence why tau = RC--Dylan2106 (talk) 23:47, 18 March 2008 (UTC)
- ^ See Equation 18, Roura, P. (2000). "How long does it take to boil an egg? A simple approach to the energy transfer equation" (PDF). Eur. J. Phys. 21: 95–100. Retrieved 2007-05-26.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Buay, D. (2006). "How long does it take to boil an egg? Revisited" (PDF). EUROPEAN JOURNAL OF PHYSICS. 27 (1): 119. Retrieved 2007-05-26.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help)