analog feedback temprature regulator question

[yefj]

Hello, I am looking for a differential feedback temprature regulator project which explains the theory best it could and give practical example in simulation.
I am looking to design a very precise temprature regultor up to 1Kelvin.
Is there some material of a project I could try to learn it?
Thanks.

 

[FvM]

Temperature control plants can be quite different, I doubt there's a specific theory, just basic control engineering.
Important parameters are heater time constant, power supply and power control method, disturbance values. Depending on their relation, 1 K temperature accuracy can be very easy or demanding.

 

[D.A.(Tony)Stewart]

There is no universal solution.
Heat can be internal from pulsed power of the device and made be added or subracted with conductive sink/sources, convection and forced air. The solution requires a very good model of the problem and disturbances.

For SC-cut Xtals in OCXO ovens, they used double ovens with an elevated max temp. above ambient. That allows them to remain temperature stable better than 1e-11 in frequency.( if I recall)

For AT-cut Xtals in a can all you need is an 805 resistor and thermistor on a Kapton FPC inside styrafoam to ovenize it with a bridge (proportional) regulator to be less than 1 PPM in a few seconds.

For a YIG Oscillator being a 0.5 mm spherical crystal ball surrounded by an electromagnet in a metal nclosure, you need something very different.