AC adaptors (also known as plug packs or sometimes power bricks) are the little black boxes that come with
your cell phone and a host of other appliances. They are a cheap, easy, and reliable solution and can be
purchased from any good electronics vendor. Typically, they will provide an output voltage somewhere in
the range of +5 VDC to +12 VDC and can supply a current of up to a few Amps, depending on the
particular plug pack. Choose one that will supply an appropriate voltage and current for your system. One
caveat with plug packs is the polarity of the connector. Most plug packs have the positive voltage on the
center of the connector jack and ground on the outside. Other plug packs have the exact opposite
arrangement! Not knowing which you have could lead to disastrous consequences for your embedded
system. As always, check the technical data and, if in doubt, use a multimeter to check the output polarity
before connecting it to your system.