|
Looks good Jo. 5C is very low indeed. My set up is controlled by a microcontroller that I program and a few additional components. I have come up with an algorithm to keep the temperature on target/setpoint with changing ambient temperature.
Your set up should do the same. I see some up/down buttons and a Set button. I'm guessing it will read cold finger temperature and maintain it from what I can see. Should work a treat.
The PWM value is the same for a given temp differential for a particular set up. Same energy requirements.
My program estimates the PWM value to maintain setpoint based on the difference between ambient and setpoint temperatures and drives cold finger temp down at 100% and calibrates PWM based on any tendency for cold finger temp to wander up or down from set point - it looks at the difference between setpoint and cold finger temperature and adds or subtracts from the estimated value and uses that as the new PWM value and so on. The tendency is to dither either side of setpoint
I just like the pain of designing my own system - glutton for punishment.
Last edited by rcheshire; 28-10-2013 at 09:43 PM.
|