Hey,
I would like to know how I can determine and control the temperature of a wire at a specific point of temperature.
I want to control the temperature from 100-300 celcius.
This can been achieved from the ampere load of the wire?
Or please send me your opinion of how it can done in a different way

 

Are you using Nichrome wire (at that temperature, you better be)?

 

Yes! And I've done it to a high degree of accuracy (within 1C up to 1000C for a *very* small piece of platinum wire).

The trick is to alternate between 'heating' and 'measuring' very quickly (faster than the thermal time constant of the wire). Use a high current voltage source for heating, and a precision low current source for measuring. You may need to use a "Kelvin" connection to eliminate errors due to connection resistance. And, the resistance vs. temperature curve may not be linear for the wire material. A lookup table solves this.

 

You mean you managed to control the wire temperature from 1c to 1000c?
I want to control the temperature of a wire kanthal wire or Pure Nickel Wire Ni200 (NON RESISTANCE)
I want to control through a source MOSFET that is capable to variably change the voltage to a specific current,so as to increase the temperature to a specific point that is from 100-300c
Can you be more specific?Sorry but me English are not the best

 

You mean you managed to control the wire temperature from 1c to 1000c?

No. The wire temperature (via resistance) was measured, and controlled, between room temperature and 1000C with a resolution of 1C (and an accuracy of about 5 to 10C).

I want to control the temperature of a wire kanthal wire or Pure Nickel Wire Ni200 (NON RESISTANCE)
I want to control through a source MOSFET that is capable to variably change the voltage to a specific current,so as to increase the temperature to a specific point that is from 100-300c

My approach used a PWM operating about 20khz. The on (heating times) were about 4 to 10 uS. The measurement was made during the off times.

A PID algorithm was used to maintain the temperature (via adjusting the PWM on time) at a given set point in approximately 1C increments.

This was all driven via a PIC MCU.

 

Thanks a lot for your quick reply.
Do you sell the PID algorithm I am very interested.
I want to do exactly the same thing.
Can you pm me?

 

Thanks a lot for your quick reply.
Do you sell the PID algorithm I am very interested.
I want to do exactly the same thing.
Can you pm me?

No...I don't sell my code. I'm just here to give you ideas...

 

Sorry I did not want to insult you my apologies.I just work on this project a long time now and I am really confused.
But you have helped me a lot with your answers.

 

I am sure my electronic engineer and friend will come up to somenthing with this idea