Appropriate power supply for experimenting?

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Hi! Our family is doing lots of Arduino and other small electronic projects these days, and we’d rather not use up our batteries while we’re learning. I’m trying to understand the differences among these options:

  • - the inexpensive “wall wart” adapters (we have plenty of those lying around, as well as a couple of variable-voltage ones)

  • - the big benchtop DC power supplies that seem to cost 10 times as much or more

  • - the do-it-yourself conversions that use an old PC ATX power supply

    • Can anyone help us understand the pros and cons of each of these? Any recommendations for particular brands or models? What kinds of cables / connectors would we want to have?

    Thanks!

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    1. These are best for finished devices. Not much current. Most are 1 or less amps.

    2. These supply lots of current if you need it. I have 2 of them and use these more than anything else. You get the voltage you need.

    3. This is the cheapest for supplying lots of current. Most of electronics hobbyists have some laying around. I think I have around 5.

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    Add a couple of notes:

    1. Wall warts - dirt cheap, but the outputs aren’t usually that ‘clean’, lots of ripple, and if they are actually dirt cheap, the output voltage/current probably isn’t going to be what’s listed. Use caution and use a meter to verify what’s what.

    2. Find a cheap-ish one on eBay. I think the best thing about those is that you can easily limit the current to your ‘new’ project. Say you accidentally shorted something on the board and just hook a battery up to it. Could possibly have instant smoke. With current limiting, you limit the current to say 1/10 amp, turn it on, and see what happens. Or a guy could always just checks ohms across power / ground.

    3. Also easy and well documented on the net. But, those things can really pump out a lot of juice. If you’ve got a short somewhere, the ATX power supplies will no doubt help you find it!!!