The heart of the sous vide cooker is a digital temperature controller. You can easily find them on eBay for less than $25, including shipping. Just be sure the controller you buy operates at 110V, and can display temperature in degrees Fahrenheit (if that's what you want). http://www.ebay.com/sch/i.html?_nkw=temperature+controller+110v&_sacat=0&_odkw=temperature+controller&_osacat=0&_from=R40
Notice how the controller has 8 screw terminals (second picture).
3 & 4 - These terminals give the device power to operate.
7 & 8 - The temperature sensor connects to these terminals.
1 & 2 - When the controller senses that the temperature is below the set temperature, it closes this relay. When it's at (or above) temperature, is opens this relay. We'll use these two terminals to route power to an outlet.
- We'll also need an enclosure to put everything into. I used a 4x4x4 electrical box I purchased at Lowes for $9.
- I like a single outlet. I got this one from Home Depot for $3. I had to cut the tabs a little to make it fit in the box.
- This is a plug like you find on computers. Get these from eBay, too. They should be less than $1 each. http://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l2736&_nkw=c14+receptacle
C13 power cord
- If you don't have one around, you should be able to pick one up for a couple of bucks. Check eBay or MonoPrice.com.
#4-40 x 3/8" screws
- You'll need a couple of screws to connect the C14 receptacle to the box.
14 AWG wire
3 female disconnects
- Optional, but very helpful