How a DIY Sous Vide Controller Works
A PID (proportional-integral-derivative) temperature controller reads a waterproof temperature probe and switches a connected outlet on and off to maintain a precise target temperature. Plug a slow cooker into that outlet and the slow cooker becomes a sous vide bath. The PID can hold temperature within 0.1 C (0.2 F) of the setpoint indefinitely, which is comparable to commercial units that cost ten times more. The total bill of materials runs $30 to $45.
0.1C
Parts You Need
Buy a Rex-C100 or Inkbird ITC-106 PID temperature controller, a 25-amp
Parts You Need
Buy a Rex-C100 or Inkbird ITC-106 PID temperature controller, a 25-amp solid-state relay (SSR), a DS18B20 waterproof temperature probe, a project enclosure box, an AC power cord, a grounded outlet, and a length of 14-gauge wire. The SSR handles switching
Wire the Control Circuit
The PID controller runs at 12V DC.
Wire the Control Circuit
The PID controller runs at 12V DC. Connect the 12V input terminals to a small AC-to-DC power supply inside the enclosure. Connect the SSR control input terminals to the PID output terminals (usually labeled AL1 or OUT1). Wire the temperature probe to the
Wire the AC Load Circuit
The SSR switches the 120V or 240V AC line that powers your slow cooker.
Wire the AC Load Circuit
The SSR switches the 120V or 240V AC line that powers your slow cooker. Connect the incoming AC hot wire to the SSR load input. Connect the SSR load output to the hot terminal of the outlet installed on the enclosure. Connect neutral directly through to
Program and Calibrate the PID
Power on the controller and enter the settings menu.
Program and Calibrate the PID
Power on the controller and enter the settings menu. Set the input type to match your probe (usually type K thermocouple or NTC 10K for DS18B20). Set the output type to SSR. Run the auto-tune function by placing the probe in water and activating
Safety Check Before First Use
Confirm all AC connections are insulated with no bare conductors exposed
Verify the enclosure lid closes securely over all wiring
Check that the ground wire is connected at both the outlet and enclosure
Test the outlet with a lamp before plugging in the slow cooker
Confirm the SSR is mounted to the enclosure wall or a heatsink for cooling
Never operate with the enclosure lid open while powered