Wednesday, June 27, 2012

Sparkfun Bench Top Power Board Kit [Review]

If you’re anything like me, you’ve got more than a couple desktop computer power supplies laying around. Sparkfun has a kit that's tailor made for the frugal tech scavenger tempted to use one of those old power supplies for something other than a PC. Sparkfun’s Bench Top Power Board Kit turns your old PC power supply unit (PSU) into a bench power supply. Let’s check it out.

PC power supplies have been used to power all kinds of other things for a long time. Connecting the green wire in the ATX connector to one of the ground wires is usually enough to get power out of the supply without plugging it into a motherboard. Sometimes a minimum load is required for the supply to operate properly. Easy, inexpensive (geeks usually have one or two laying around), and ample power makes PC power supplies desirable for all kinds of stuff.

The Sparkfun Bench Top Power Board comes in the signature red Sparkfun box that doubles as an enclosure for the kit. Cutting along the dotted lines provides access to the assembled kit’s power connector and binding posts. I’m not sure why anyone would want to hide this decent looking kit in a cardboard box, but I give Sparkfun points for ingenuity.

The kit includes the printed circuit board, 4 red and 4 black binding posts, 4 fuses (one for each of the power rails), fuse holders, an LED and resister, 4 screws and standoffs, a 24 pin ATX connector, and an instruction booklet. The kit does not include the wire required to connect the binding posts to the circuit board.

The product page on the Sparkfun website states that assembling the kit, “ shouldn't take more than 30-45 minutes for a beginner.” This kit took me an hour to assemble. There’s not much to the kit, but there were a few factors, both mine and with the kit, that helped the assembly take me longer that it should have.

I think the biggest issue was that it was after 11:00pm when I started putting this kit together. Getting up at 4:30am makes 11:00pm very late in the day for me. Any frustrations I met with were probably amplified a bit by fatigue. For some reason, I had a heck of a time getting solder to stick to the black wire I was using. There red wire I used, same wire with red insulation, worked fine.

The binding post spacing was a little frustrating as well. Typically, sets of two binding posts are spaced 0.75” apart to match the spacing of dual banana plugs. The mounting holes in the PCB for the binding post are much closer together at only 0.5" apart.  Not only does this prevent the use of dual banana plugs but it makes tightening down the binding post nuts a challenge. An open end wrench did the trick but it was much more difficult than it had to be.

Other than the issues I have with the binding post spacing, the Sparkfun Desktop Power Board Kit is a great little kit if you’re looking to use an ATX PSU as a bench top power supply. For the most part, the kit is fun and easy to assemble, and the instructions are straightforward and easy to follow. The usefulness of an ATX PSU as a lab or bench power supply is debatable, but the Sparkfun Desktop Power Board Kit breaks out the 3.3V, 5V, 12V and -12V rails nice and cleanly and looks pretty good doing it.

Links: Sparkfun Desktop Power Board Kit Kit-09774

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