Dual Polarity Power Supply

This dual polarity power supply is easy to build, requires few parts, and is adjustable from 0-15 volts. It is great for powering op amp circuits, as well as other circuits that require a dual supply voltage.

Schematic

This is the schematic of the Dual Polarity Power Supply

Parts

C1,C2_______2200uF 35V Electrolytic Capacitor
C3,C4,C5,C7_1uF 35V Electrolytic Capacitor
C6,C8_______100uF 35V Electrolytic Capacitor
R1,R4_______5K Pot
R2,R3_______240 Ohm 1/4 W Resistor
BR1_________2A 30V Bridge Rectifier
U1__________LM317 Adjustable Positive Regulator
U2__________LM337 Adjustable Negitive Regulator
T1__________30V Center Tapped 2 Amp Transformer
S1__________SPST 2 Amp Switch
MISC________Heatsinks For U1 And U2, Line Cord, Case, Nobs For Pots, Wire.

Notes

1. Since this project operates from 120 (or 220, or 240, etc.) volts AC, it MUST be built inside a case.

2. U1 and U2 get quite hot and will require heatsinks. A fan is usually not needed.

3. You can, of course, add a volt and amp meter.