Electronics 01
Why Is the RC Time Constant 63%? The Math of 1 − 1/e
63.2% is 1 minus 1/e, the point where an RC curve would have finished if it kept its starting slope. Why e appears, and why 5τ is not always enough.
rc circuits
Electronics 02
RC Low Pass Filter Cutoff Frequency: What −3 dB Means
fc = 1/(2πRC) is where the output is 0.707 of the input, half power and −45°. Why the slope there is only 10 dB/decade, and how loading moves it.
Electronics 03
Button Debounce Capacitor Value: How to Size the RC
Switches bounce for 1.6 ms on average and 6 ms or more at worst. How to size the debounce R and C from Schmitt thresholds, and why 10k with 100 nF is too short.