LM 317 Adjustable Regulated Power Supply

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The LM 317 is a handy IC for use in small power supplies since it can be adjusted with only 2 resistors to between 1.2 and 37 volts. Here's a link to a web based calculator to determine the required resistors for a specific application, http://www.electronics-lab.com/articles/LM317 .

Here's an image of a PCB I made using my laser printer.

Here's the image file needed to print the PCB.

I added board holes for capacitors C1 and C2, although if you're using a clean power supply such as a battery, and all the runs are short, you don't need the capacitors at all, so just omit them (leave the holes open, don't short them out).

Here's a completed board next a bare board.

Vin is your positive power in, the power in should be at least 2 volts higher than the desired regulated output voltage. Vout is the regulated positive power out, and the two terminals marked - are ground for power in and power out. Depending on your application, you may need a heat sink on LM317, while it can output 1.5 amps, it does generate some heat even well below those levels.

Here I printed the LM 317 circuit on a larger board to accommodate an OEM GPS unit. The GPS requires regulated 3.3 volts. I will need to add a heat sink to the LM 317 as it starts getting hot after 5 minutes or so.