Capacitor charging and discharging time calculation formula - Database & Sql Blog Articles

SMD aluminum electrolytic capacitor

Tantalum capacitor

Let V0 be the initial voltage value on the capacitor;
V1 is the voltage value at which the capacitor can eventually be charged or placed;
Vt is the voltage value at the time of time t.
then,
Vt="V0"+(V1-V0)* [1-exp(-t/RC)]
or,
t = RC*Ln[(V1-V0)/(V1-Vt)]

For example, a battery with a voltage of E charges R0 to a capacitor C with an initial value of 0, and V1 = E, so the voltage on the capacitor at time t is:
Vt="E"*[1-exp(-t/RC)]

For another example, the capacitor C whose initial voltage is E passes through R discharge V0=E, V1=0, so the voltage on the capacitor at time t is:
Vt="E"*exp(-t/RC)

For another example, the capacitor C with an initial value of 1/3Vcc is charged by R, and the final value of charging is
Vcc, what is the time required to charge 2/3Vcc?
V0=Vcc/3, V1=Vcc, Vt=2*Vcc/3, so
t="RC"*Ln[(1-1/3)/(1-2/3)]=RC*Ln2
=0.693RC

Note: The above exp() represents the exponential function with e as the base; Ln() is the logarithmic function with e as the base.