Regulated Dual Power Supply

The objective here is to build a dual power supply that generates regulated +12 volts and -12 volts from AC mains. Such a supply is a very common requirement in all those circuits that use opamps.
Each output in the circuit has a current delivering capability of 250mA .

Components

Description

The unregulated AC/DC power supply part of the circuit consist of a transformer that steps down the power to 15 volts across a center tapped secondary windings I.e. The two half’s of the secondary winding with opposite polarities , diode D1 to D4 that rectifies the AC providing full wave rectification to produce a positive and negative output, capacitors C1 and C2 provide filtration. C3 to C8 are decoupling capacitors. IC-1 is a fixed output positive three terminal regulator whereas IC-2 is a fixed output negative three terminal regulator.

Other variations of the circuit

The same circuit can be used to produce (+5V,-5V) ,(+9V,-9V),(+15V,-15V),(+18V,-18V) and (+24V,-24V).what you need to do is to use different type nos. for the two regulators’ and a different transformer.