Posit: a device containing capacitors is running perfectly, and the turned-off. It then sits for a period of time on a shelf in the garage, and some months later is opened for dissection. And/or, I charge big honkin' caps on the bench, get distracted, go on a business trip, and return a few weeks later. In that case, r=infinity.
What formula can be applied to determine what charge still remains?
Waaaay back in 2011, #12 was kind enough to post:
The formula written on my wall says, Vo=dV (e^-t/rc)
so Vcap = original Vcap times e to the negative time over (resistance x capacitance)
Would the above apply? I'm not concerned with zapping myself - I know how to sweetly and gently discharge a cap! I'm focused on "how long will a charge (and "what charge?") will remain?" on those bigger ones.
What formula can be applied to determine what charge still remains?
Waaaay back in 2011, #12 was kind enough to post:
The formula written on my wall says, Vo=dV (e^-t/rc)
so Vcap = original Vcap times e to the negative time over (resistance x capacitance)
Would the above apply? I'm not concerned with zapping myself - I know how to sweetly and gently discharge a cap! I'm focused on "how long will a charge (and "what charge?") will remain?" on those bigger ones.