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Old 03-28-2010, 05:09 PM
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Default RC Circuit - Post-Lab Questions
What is the voltage across a capacitor after a time of two constants when charging from zero voltage. When discharging from a fully charged condition?

VCapacitor = VBattery(1 - e-t/2T)

VCapacitor = VMaximum * e-t/2T

I'm confused at how to start. I can do the algebra...

Charging from zero voltage - so would I set VMaximum to 0? Wouldn't I need to know VBattery? That wouldn't make sense to me. If I can get an idea of how to approach this problem, I should be able to solve it no problem. Thanks!
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Old 03-28-2010, 06:29 PM
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RC is the time constant. In the problem you have to use t = 2RC.
Last edited by sa-ri-ga-ma; 03-29-2010 at 06:42 PM.
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Old 03-28-2010, 06:35 PM
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Quote:
Originally Posted by sa-ri-ga-ma View Post
RC is the time constant. In then problem you have to use t = 2RC.
Okay, so:

VCapacitor = VBattery(1 - e^-2RC/RC)
VCapacitor = VBattery(1 - e^-2)

Then just simplify?
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Old 03-28-2010, 06:47 PM
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Quote:
Originally Posted by chrisfnet View Post
Okay, so:

VCapacitor = VBattery(1 - e^-2RC/RC)
VCapacitor = VBattery(1 - e^-2)

Then just simplify?
Yes. It is correct.
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