I have currently two power resistors, 12 ohm, 25 W, this kind of product: http://fr.aliexpress.com/item/10-Oh...2502805027.html?spm=2114.44010308.4.35.tK9mXc
I am trying to maintain the temperature inside an enclosure in a given range, say 37.5°C .. 38.2°C . It must never go higher than 38.5°C
The problem I have with these resistors is that the inertia is too high. If I stop the current when the correct temperature is reached, the temperature keeps on climbing because some heat is still stored in the resistors heatsink, and I overshoot the target temperature by 2°C for a short amount of time. I dissipate the heat with a 12V PC fan . The problem also exists in the reverse direction. When the temperature reaches 37°C, it takes too much time to heat the resistors, and the temperature drops to 35°C.
The heat is currently provided only by these two resistors.
Can you suggest me a way to have a more fine grained control on the resistors temperature, and the temperature inside the enclosure in general ? Currently the Rs are wired in parallel to a 18V/65W DC power supply, and controlled by a temperature controller Willhi Wh 7016, but I intent to replace it with an Arduino.
I am trying to maintain the temperature inside an enclosure in a given range, say 37.5°C .. 38.2°C . It must never go higher than 38.5°C
The problem I have with these resistors is that the inertia is too high. If I stop the current when the correct temperature is reached, the temperature keeps on climbing because some heat is still stored in the resistors heatsink, and I overshoot the target temperature by 2°C for a short amount of time. I dissipate the heat with a 12V PC fan . The problem also exists in the reverse direction. When the temperature reaches 37°C, it takes too much time to heat the resistors, and the temperature drops to 35°C.
The heat is currently provided only by these two resistors.
Can you suggest me a way to have a more fine grained control on the resistors temperature, and the temperature inside the enclosure in general ? Currently the Rs are wired in parallel to a 18V/65W DC power supply, and controlled by a temperature controller Willhi Wh 7016, but I intent to replace it with an Arduino.