Right, I have a very simple circuit that I aim to use as a delay circuit, everything was going fine until I started to over think it all and now I have totally confused myself and it is slightly embarrassing.
This is my circuit:
As you can see, nice and simple. I know the time constant of the capacitor is RC to reach 63% of the voltage, but my issue is what is the voltage that it is reaching 63% of? I initially thought the 2V supply (capped at 1V though) that I am using at R2, but then it would charge to 1V in less than RC (not what I want).
I take the time constant as \$1M\Omega \times 1 \mu F = 1\$s but would that be the time to charge to 63% of 2V (but cap out at 1V) or 63% 1V (i.e. take 5 times longer to get to 1V)?