Project-1: Building LED flasher using IC555
In this project Observe calculations and oscilloscope waveform. When both potentiometers at max wave form time period would be
0.693*(R1 + 2R2)*C = 1000 ms
While capacitor charging Vc = Vs(1-e^(-t1/RC)). That means for charging the capacitor up to 1/3 of Vs we have e^(-t1/RC) = 0.66 or t1 = 0.41522RC. And for charging up to 2/3; e^(-t2/RC) = 0.33 or t2 = 1.10866. Thus t = t2 - t1 = 0.69315RC.
While discharging Vc = V0e(-t/RC). Thus to discharge from 2/3 Vs up to 1/3 we have e^(-t/RC) = 0.5 or t = 0.69315RC