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JLD612 Behavior Questions

Posted: Mon Mar 17, 2014 2:46 pm
by Lutz
I'm familiar with control theory in general but have a question on how the JLD612 determines the output state.

Let's assume that my target temp is 50C and my P band is at 10% (I and D times both minimized). That would then translate into a 5C band and the output should be adjusted down starting at 45C
45C = 100%
46C = 80%
47C = 60%
48C = 40%
49C = 20%
50C = 0%

=> How is the output changing between 45C and 50C?

To me, there's two possible outputs:
1.) Mathematical rounding. Meaning if calculated power is >=50%, power is on. Example would be that power is on until 47C and once temperature is at 48C, power would be off with
2.) Duty cycling. Meaning that the power is on for x% of the defined control period (ot parameter). Example with ot=2seconds at 47C, power would be on for 2*60% = 1.2 seconds and off for 0.8 seconds.

Re: JLD612 Behavior Questions

Posted: Mon Mar 31, 2014 7:29 am
by Lutz
I have played around with my controller and it seems the answer is 2.)
Watching the approach as my temp goes towards the target, I see the SSR cycling on and off with the closer I'm getting towards SV, the more off periods I'm noticing.

Re: JLD612 Behavior Questions

Posted: Sat Apr 05, 2014 9:12 pm
by richiem
Yep. Good call.