Hobbyist electronics projects need robust, reliable power supplies for prototyping and testing. I learned how to build this circuit from the Basic Analog Circuits class at ITP taught by Eric Rosenthal, but took it several steps further in building a solid enclosure and integrating a voltage meter. Now it lives on my desk, ready to power most small projects I’m working on.

You’ll see example shots of point-to-point wiring of components to perfboard while following a schematic for this power supply. A wood enclosure is built, and Adafruit’s Mini Volt Meter, Vout posts, and a potentiometer are mounted in the final product.

Parts List:

  • One 3×5″ perfboard
  • LM317 variable voltage regulator
  • BR805D Bridge Rectifier
  • Heat Sink
  • 120 VAC to 24 VDC transformer (mine is part number LP-575)
  • Power cable
  • Two 1000 microfarad capacitors
  • One 0.1 microfarad capacitor
  • One 1 microfarad capacitor
  • One 100 ohm resistor
  • One 5k ohm variable resistor
  • One 1N4002 diode
  • 1/2″ plywood
  • 1/8″ wood or MDF
  • six half inch wood screws
  • 8 1/2″ long x 1/8″ wide nuts and bolts
  • Plastic knob
  • Mini volt meter from Adafruit Industries