LM317 is the most used and easily available adjustable voltage regulator. Here I’ve designed a simple PCB for the regulator with surrounding diodes, capacitors, resistors, etc. In this board, the voltage adjustor connector is given into which a potentiometer can be attached for variable supply.I’ve designed the board from the given application circuit in the LM317 datasheet.
Download Eagle design files.Here I’ve printed the front and back of the PCB’s layout mirrored for toner transfer process. This time I used Pulsar products instead of ordinary photo papers and it is an excellent key to good quality PCBs.
Here’s the second Pulsar product I used. It’s a protective foil called Green TRF. This is iron-ed to the toner and it gives an additional layer of protection to the layout from the etchant.
And this is how the PCB looks like when populated.