## maintain constant Power in varying load

Hi,

I'm having some questions about the way I could achieve to maintain the power in a resistor constant. My problem, is that the resistor is quite small (less than 100ohm at room temperature). When running, the resistor, a heating resistor, heats up to 300celcius.

So, the resistor change in function of the temperature. So, to maintain that temperature, I want to keep the power of the resistor constant.

I have some ideas to achieve this, but I have some misunderdstanding so I miss something.

Here is my mind :

RL = Resistor Load (heating resistor)

1. find IRL : adding an Rsense of about 1ohm serially with the RL. 1A = 1V on the ouput of the opamp
2. multiply the IRL with the VRL. Obtain Power 1W = 1V.
3. find delta Power (substract Power_Setpoint from Power (step2))
4. ?????? -> using (step 3) change the current or the voltage applied to the Rsense to obtain the perfect power.

I though to use a microcontroller to control this, but I was wondering some precision issues...

So, do somebody have some suggestions ?
Do some circuit do this ?
Am I doing this right ?