This very simple adjustable power source will serve every craftsman in his beginnings. It’s a „catalog“ circuit diagram by an anti-parallel diode against back-breaking of the stabilizer. Link to the datasheet LM317: http://www.ti.com/lit/ds/slvs044x/slvs044x.pdf
The input voltage of the adjustable power supply must be 1.5V higher than required at the output.
Connect DC voltage to the input terminals (K1), C1 and C2 function as filter capacitors. The values of R1 and P1 set the output voltage of the stabilizer, C3 is used to filter the output voltage.
Printed circuit board:
Placement plan and PCB are at 1:1 300 dpi (How to print a PCB design can be found in the post How to print PCB design). Real size PCB is 43,2 x 25,1 mm.
|P1||5k linear potentiometer|
|K1,2||screw terminal for PCB, RM=5mm, 2 pin|