Formulas used
- RC: tau = R x C
- RL: tau = L / R
- t = -tau x ln(1 - p), cut-off frequency = 1 / (2 x pi x tau)
Frequently asked questions
How long until a capacitor is fully charged?
In theory never, but after 5 time constants it is above 99 percent charged.
What is the cut-off frequency?
The frequency where a simple RC or RL filter passes 70.7 percent of the signal, which is a 3 dB drop.