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weeb0
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how to 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 ?
Thank you for your help
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 ?
Thank you for your help
Last edited: