Your 5 volt system can wield great power with this big beefy relay board. How does 20 amps at 220VAC sound? The SparkFun Beefcake Relay Control Kit contains all the parts you need to get your high-power load under control.
The heart of the board is a sealed, SPDT-NO 20A Relay. The relay is controlled by 5V logic through a transistor and an LED tells you when the relay is closed. This is a kit, so it comes as through-hole parts with assembly required which makes for some nice soldering practice. Screw terminal connectors on either side of the board make it easy to incorporate into your project.
Note: There are some pretty beefy traces connecting the relay to the load pins, but the 2-pin terminals are only rated for 8A max! If you plan on connecting a larger load you'll need to solder directly to the board. As always with high current and voltage, play it safe and use your judgment when deciding how much of a load you want to put on a board.
Note: Although we have revised this PCB to provide better isolation for the high voltage traces, this board is really meant for someone with some experience. If you'll uncomfortable soldering or dealing with high voltage, please checkout the PowerSwitch Tail II. The PowerSwitch Tail II is fully enclosed making it a lot safer.