Here is the standard dual power supply using the Positive and
Negative Voltage regulator ICs. It can give +12 volt and – 12 volt DC
with a common ground.This power supply is ideal to power amplifier
circuits that require well regulated dual power supply. It can give 1
ampere current to the circuit.
IC2 is 7912 negative regulator and its pins are slightly different from 7812. See the connection in the diagram. Regulated outputs from the regulator ICs are available from pin 3 which can be used to power the circuit. Capacitors C3 and C4 act as noise filters to give clean DC.
14-0-14 volt 1 Ampere step down transformer is used to drop 230 volt AC
to 14 volt DC which is then rectified using the standard full wave
bridge rectifier comprising D1 through D4.Smoothing capacitors C1 and C2
remove the ripples from low volt AC.Two regulator ICs are used to
generate + 12 volt and – 12 volt DC. IC1 is 7812 positive regulator
giving +12 volt regulated output .
IC2 is 7912 negative regulator and its pins are slightly different from 7812. See the connection in the diagram. Regulated outputs from the regulator ICs are available from pin 3 which can be used to power the circuit. Capacitors C3 and C4 act as noise filters to give clean DC.