ATX Variable DC Power Supply

Every good workbench needs a dc power supply, and mine is no different.  With the upcoming projects I have in mind several things will be running off of battery power.   And rather than be constantly recharging batteries I thought it was time to build my own power source.

There is a wealth of information out there on how to use a standard ATX computer power supply.  Here are the two sources that I used:

Instructable for ATX Power Supply

Adding Variable Control

The parts were relatively cheap, and most of the things I already had lying around the house.  I decided that I didn’t want to break open the power supply and do any actual modification to it.  This way in a computer emergency I still have a fully functional psu ready to go.

For convenience sake I also wanted to add a digital display to the box so I could tell what the voltage of the variable binding post was without connecting my multimeter.  The LED volt meter I purchased from the ebay seller at sure-electronics.net, and the going rate for these is ~$10 shipped from somewhere in Asia.  So plan a couple weeks ahead!  There are several models that require different voltages to operate, and provide different input ranges for the meter.   I purchased one that was powered by 5V, and would accept a range of 0-20V for display.   Since I am only providing a maximum of 12V out, this was well within range.  The exact model number was:  ME-PM105, and you can find these in several different colors.

powersupply

Laserpup's Variable DC Power Supply

The power supply has binding posts for GND, +5V, +12V, and a variable supply from ~2-12V.  You can also connect a 3.3V post to the PSU, but I ran out of room on the project box.

powersupplyback

PSU Connection Point

To allow easy replacement of the power supply I used an atx extension cable.  The female part was used as the plug in port on the back, while the male part was removed allowing access to the wires for connections.

Here is a shot of it in action, powering up a RC transmitter!

I wonder if a vex robot is in the future.......

May 22, 2009 • Tags:  • Posted in: Projects

3 Responses to “ATX Variable DC Power Supply”

  1. Hans - May 22, 2009

    Nice work, looks cool. Do you have a part number or link to that LCD? I might recreate your project.

  2. Polymythic - May 25, 2009

    I have workbench envy. I need to build one.

  3. joe - May 26, 2009

    Hans,

    Thanks for the interest, I updated my post to include the LCD information.

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