The description about the TC is a little chalenging to me
What I want to do is take the circuit on the right and make the resistor variable. What value ohms variability to get the delay off from 1 to 20 seconds?
I also have some NTE123 trans and lots of 330uf caps.
Can I use the NTE123 in place of theses suggested 2N2222? Circuit modify to use them?
Is the diode across the relay coil needed?
I plan to put 3 of the caps in parallel to make 1000uf.
his description below which having some trouble with
"The time delay for the common emitter will be approximately 3 time constants or 3*R*C.
The capacitor value for a 15 second delay will be 15/3R = 1327 uF.