+30 VDC Power Supply

Original source from : http://www.aaroncake.net/circuits/supply.htm

When working with electronics, you always need one basic thing; power. This power supply is great for powering all kinds of electronic projects. It produces a well filtered, variable 1.2-30 volts at 5 amps. It is easy to build and the parts are realitively easy to find.


This is a schematic of the Power Supply


Part Total Qty. Description Substitutions
C1 1 14000uF or 10000uf 40 VDC Electrolytic Capacitor  
C2 1 100uF 50Vdc Electrolytic Capacitor  
C3 1 0.1uF Disc Capacitor  
C4 1 0.01uF Disc Capacitor  
R1 1 5K Pot  
R2 1 240 Ohm 1/4 W Resistor  
U1 1 LM338K 1.2 to 30 Volt 5 Amp Regulator  
BR1 1 10 Amp 50 PIV Bridge Rectifier  
T1 1 24 V 5 Amp Transformer  
S1 1 SPST Toggle Switch  
MISC 1 Wire, Line Cord, Case, Binding Posts (for output)  


1. The regulator comes in a TO-3 case and MUST be used with a LARGE heatsink. You may want to mount a small fan to blow air across the regulator (I did).

2. The filter capacitor is large. It won't fit on any board so bolt it to the case.

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

4. Since this project operates from 120 VAC, you must include a fuse and build the project in a case.