I'm planning to make a variable split power supply from a 9V DC adapter.
So far I found two easy approaches. One is with a 555 timer here:
And the other is just with two resistors and capacitors here:
I have two questions:
1-) If I want to make a variable split supply between 5V to 12V which is controlled with a poti, can I use the same circuits without changing any component values?
2-) How reliable and regulated 9V DC adapters in general? I mean should I use a voltage regulator between the 9V adapter and the splitting circuitry?