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Discussion Groups | BasicX | Charge/discharge time of a capacitor
Discussion forum for the BasicX family of microcontroller chips.
Charge/discharge time of a capacitor - David Sousa Mendes - Jan 16 12:10:07 2008
Hello again
When we use te command RCTime, the manual says that we are "measuring how long the pin stays at a certain logic level".
In the electronics classes we learn that the charge/discharge time of a capacitor equals 5 t, ie, 5*RC.
My question is: Is the time returned by the function RCTime somehow related to this t?
Cheers
BR
David M.
[Non-text portions of this message have been removed]
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When we use te command RCTime, the manual says that we are "measuring how long the pin stays at a certain logic level".
In the electronics classes we learn that the charge/discharge time of a capacitor equals 5 t, ie, 5*RC.
My question is: Is the time returned by the function RCTime somehow related to this t?
Cheers
BR
David M.
[Non-text portions of this message have been removed]
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )
Re: Charge/discharge time of a capacitor - Tom Becker - Jan 16 18:50:44 2008
> ...Is the time returned by the function RCTime somehow related to this t?
It is related to RC, yes, but not 5RC. Here's example code that
measures a pot position using a BX-24 digital input pin.
http://www.basicx.com/Products/BX-24/Code_Examples/RCtime_BX24.zip
It shows that the input pin switches at ~2.5v, which corresponds to ~70%
of RC if C is charged from 5v. In the example code, for example, RCTime
indicates ~3.47mS when RC = 5.0mS, or RCTime ~= 0.7RC .
Tom
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )
It is related to RC, yes, but not 5RC. Here's example code that
measures a pot position using a BX-24 digital input pin.
http://www.basicx.com/Products/BX-24/Code_Examples/RCtime_BX24.zip
It shows that the input pin switches at ~2.5v, which corresponds to ~70%
of RC if C is charged from 5v. In the example code, for example, RCTime
indicates ~3.47mS when RC = 5.0mS, or RCTime ~= 0.7RC .
Tom
(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )