Adjusting oven temperature with "Infinite switch control"

[hamsiii]

Hello all,

I wanted to implement a control box to an oven that heats 400-500 degrees Celcius. I have thermocouples (J Type) inside the oven and it has 2 terminals outside. I came across a component called "infinite control switch" that can work in my situation, which acts as a variable resistor, I guess. I do not want to use any microcontrollers and also integrate an analog display to that box that reads the oven's temperature. So, box should adjust the temperature and I should see it on the analog display.

The circuit should start with a terminal of the thermocouple, then with a series connected infinite control switch and parallel connected analog display, ended with other terminal of thermocouple. Do I need anything else, as I am confused that 3 elements will work in this case.

To sum up, my question is; can I find a commercial product despite working on this project, otherwise can I use just these components to implement a box explained above?

Thanks in advance.

 

[GUMY]

What is the power and volatge rating of the heater element?

 

[hamsiii]

The oven will work with 220/240Vac with 5A (I do not know the exact current rating). Heater is just resistors inside protective product.

 

[GUMY]

Infinite control switch is not a variable resistor, it is bimetal driven on/off switch, which controls power delivery to load. It is a simple open-loop regulator thus it can not regulate temperature of the owen.

 

[hamsiii]

It can be used as adjusting the power of the oven, then. So, we need to adjust the temperature by changing the current of the oven, right?

 

[GUMY]

The basic problem is, how to close the regulation looop, or in other words, how to deliver the temperature measurement to "Infinite switch". I don't see any posibility to use this element for such application.

 

[schmitt trigger]

From a website description:

An infinite switch or infinite controller is a type of switch that allows variable power output and is so called because its average output is infinitely variable rather than being limited to a few switched levels. They utilize a bi-metallic strip conductive connection across terminals that disconnects with increased temperature. As current passes through the bimetal connection, it will heat and deform, breaking the connection and turning off the power. After a short time, the bimetal will cool and reconnect. Therefore, infinite switches vary the average power delivered to a device by oscillating quickly between on and off states.

So no, this is not a variable resistor, but rather an on/off switch.

Thermocouples produce miniscule amounts of currents. You can use a 0 to 50 microamp analog movement, with a suitable burden resistor and then with another accurate thermometer calibrate the scale to degrees Celsius.

EDIT;
as you can see from my avatar, I LIKE analog meters.
However, nowadays it is expensive to get GOOD analog meters.

 

[FvM]

If you have a temperature measurement in your oven, it would be better to perform temperature control instead of power control.