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Temperature Control (Sous Vide)

I have been talking about this for ages… threatening to build it… even ordered parts.  But, it wasn’t until a couple of weeks ago when Drew brought his Sansaire over and cooked some eggs for us that I finally got the motivation to start work on this project.

There are 101 ways you could do this.  I’m going for cheap.  My temperature sensor is a super-cheap PT100 PTC sensor.  I am running it in a wheatstone bridge connected to a differential amplifier tuned to get the best resolution out of the temperature range I’m interested in. (49C – 74C)  The output of that goes to a Nano clone, which currently only turns a Solid State Relay on and off.  (I plan to use PID in the future)  The relay turns a slow cooker on and off.  This tiny one really isn’t hot enough, but I’m giving it a try today.



I am monitoring the whole thing over the USB/Serial port with a quickly hacked together windows application.  Future plans including adjusting the setpoint and tuning the PID from this application.



So, in about an hour, I should have some perfectly cooked eggs!




It worked!  These were cooked to 64.5C for one hour.
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