Home Projects Power Dual Polarity Power Supply

 

 

Dual Polarity Power Supply

source: http://www.aaroncake.net/

 

 

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


Part

Total Qty.

Description

Substitutions

C1, C2

2

2200uF 35V Electrolytic Capacitor

C3, C4, C5, C7

4

1uF 35V Electrolytic Capacitor

C6, C8

2

100uF 35V Electrolytic Capacitor

R1, R4

2

5K Pot

R2, R3

2

240 Ohm 1/4 W Resistor

BR1

1

2A 30V Bridge Rectifier

U1

1

LM317 Adjustable Positive Regulator

U2

1

LM337 Adjustable Negative Regulator

T1

1

30V Center Tapped 2 Amp Transformer

S1

1

SPST 2 Amp Switch

MISC

1

Heatsinks For U1 And U2, Line Cord, Case, Knobs 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.

4. U1 and U2 can only go down to a minimum of +-1.2V. If you need to go lower, you can add two 1N4003 diodes in series with the output of the regulator. The diodes drop about 0.6V each, which will allow the supply to go to 0. Note that this will also decrease your maximum output voltage by 1.2V. (Thanks to Steve Horvath for the suggestion).

Also check this LM317 Calculator

 

 
 

 

Search Site | Support us | Advertising | Profile | Books | Gadgets | Add your link here | Contact Us


IQ Technologies @ copy right 2008

Powered by Wild Host   Site Design By : FRIEND