Regulated 12V dual power supply
Some circuits require a dual power supply(eg-Op-amp ICs,pre-amps,power amps) to double the input voltage. any dual supply will have 3 outputs That are known as (+)positive, and (0V) or GND, and (-) negative. as an easy example a tda2030A(a hifi amplifier IC) will not work from a single rail powersupply because it is intented to use only with dual powersupply.
here is an easy to build dual power supply circuit, this circuit can output requlated 12V output with 1A current! The positive regulator is 7812 positive 12V regulator IC, and the 7912″ is a negative 12V regulator IC.
this circuit can be used to power pre-amps and low power amplifiers if it requires a dual powersupply,
EDIT: two heatsinks should be attached on the ICs to reduce heat and increase life