I made this circuit, with the intention of it lighting and then fading out the led after very briefly closing the switch:
This is intended for a CR2032 coin cell battery power source and the led is a normal 20ma through hole red LED, probably Vf =~ 2v.
Ignoring the one resistor in series with the power supply, what function describes how the transistor and the values of capacitor and resistor determine the led brightness and how long it takes to fade out? Like if I wanted to make it fade out 50% more quickly or more slowly, how would I change the resistor and/or capacitor?
Does the characteristics of the transistor matter?