Adjustable 7805 DC output

Description

You can, with a little modification use a 7805 regulator to generate a variable voltage output, in the example below the output can be 5v to 30v.

At higher output voltages you should fit a suitable heatsink to the 7805.

Schematic

7805 adjusatbale

Parts List

QTY  PART-REFS           VALUE                                       
---  ---------           -----                                    
Resistors
---------
1    R1                  220R                                              

Capacitors
----------
2    C1,C3               100nF                                             
1    C2                  100uF                                             
1    C4                  10uF                                              

Integrated Circuits
-------------------
1    U1                  78L05                                             

Miscellaneous
-------------
1    RV1                 5k