For many of us who don't produce things from our home workshop on a regular basis, buying a full-featured benchtop power supply seems like an unnecessary expense. However, computer power supplies are plentiful and often even free. It is extremely common to see an ATX power supply on a tinkerer's bench with wires cut to allow use of the 5V, 3.3V, and 12V lines. However, not only is that messy, it can be all too easy to burn things up if you're too lazy to keep your wires properly separated.
I've moved my project, causing the wires to move, and that 12V to come in contact with something that was supposed to be 5V on more than one occasion.
The most common solution is to make some kind of a permanent mount for your feeds. I stumbled onto this fantastic breakout board that does exactly that in a feature-rich and good-looking package. This kit by Ben Jordan costs $30 before shipping, and gives pretty much anything you would want to make your ATX power supply into a benchtop.
Ben set out to make an adapter with the following features:
- Not alter the power supply itself.
- Use an ATX connector.
- Have binding posts for each ATX power supply voltage and standby.
- Have a matching return (GND) binding post for each voltage output.
- Be capable of handling heavy supply currents.
- Have a switch circuit to make use of the ATX on/off controller.
- Have LEDs to monitor standby and Power Good signal.
- Use through-hole PCB design so you can make one for yourself easily.
I really like a few of these items. The ability to not alter the supply itself is quite nice. I can literally plug this into the power supply that is currently in my desktop if I am in a pinch. I don't foresee that as a common need, but the idea of not altering the ATX supply is appealing.
Other kits are out there do this, but they lack a power button to actually turn the unit on. Another thing I really like about Jordan's design is the ability to handle larger currents. Many others I've seen have looked a bit flimsy and made me nervous about pulling too much juice.
I'm particularly enamored with his implementation of holes for alligator clips. That is such a simple idea and well implemented, too.