Simple Temperature Controller – Sous vide

So a couple weeks ago I started experimenting with sous vide cooking – simply using ziplock bags and the store by turning it on/off. Wanting to do more and manage it less, I’ve decided build myself a temperature controller that’ll turn on/off a cooking element.

A sous vide controller is essentially just a temperature controller that turns on/off a heating element when the temperature is below a certain threshold and turns off once it reaches that temperature. What I’m going to do is take the STC-1000, which is a pre-assembled temperature controller from Amazon (priced similarly on eBay but faster shipping on Amazon), and then run it to a power outlet.

Parts list:
STC-1000 ($28 or another temperature controller)
Extension cord (rated 1000W or higher – that’s 8.5A or more – at most $8.50 for a 10-foot or 15-foot cord)
Twist wire connector (Marrette) (minimum 3 yellows) ($3 for 20 or Amazon has them for $7 for 75)
Electrical tape (optional but recommended)
Case (optional but recommended)

That’s it, spending about $40 plus tax for a pre-made controller, that will be easy to implement in our design.

For my controller I opted to use the cardboard box the STC-1000 came in as a temporary thing – As I forgot to look for a case when  I was at home depot – but shouldn’t be a problem so long as it doesn’t spark while in use.

I know it’s obvious but here’s the blurb from the cord:

DANGER: Electrical cords can be hazardous.
Misuse can result in FIRE or DEATH by ELECTRICAL SHOCK.

The label will also say not to modify the cord… but oh well. Anyways, here’s a poorly designed schematic created in MS Paint.

Modified for school project
Modified for school project – Temperature Controller Schematic

You also want to cut out the shape of the controller on the case (in my case the cardboard box it come in) and slide the controller into the box then wire everything together as shown in the schematic. If you don’t have any electrical tape try to expose the least amount of copper wiring while still getting a good connection. I also used some extra cable from the original extension cord by cutting the cord into thirds. The middle third was extra wire used to connect to the temperature controller. Don’t forget to connect the temperature probe.

Look forward to another post about a controller that costs under $15 or an immersion circulator in the future.