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Temperature control

Posted: Thu May 09, 2013 5:30 pm
by jjw
Does anybody have ideas how to change the code so that when the temperature is changing out of its range the change will take place only one temperature area at time when temperature is rising up or cooling down Now it’s jumping two to three temperatures areas. Maybe somehow forcing it from one temperature area to the second area when temperature is changing….

jjw

Re: Temperature control

Posted: Fri May 10, 2013 8:12 am
by jgu1
Hi jjw!

Send you a PM concerning the solartracker. :D

Jorgen

Re: Temperature control

Posted: Sat May 11, 2013 12:17 am
by medelec35
Hi jjw,

Can you post some example temperatures and what its doing.

Also examples with same temperatures but what you would like to happen.

Martin

Re: Temperature control

Posted: Sat May 11, 2013 5:14 am
by jjw
Hi Martin,
This is an example of our last tests temperate was rising normally into 298 C and stepper controls took place primary damper went to 70 %. Due to the fire woods quality the temperature jump strait into some 313 C and only that temperature areas controls took place primary damper 50%. This is just a point if the temperature will rise more than one temp area it will loose stepper motors positioning when cooling down process is happening. That’s the reason I want it behave so that although the temperature will rise more than temp area all the controls must be happening all lower temp areas also. Same thing when cooling down.

jjw

Re: Temperature control

Posted: Sat May 11, 2013 11:53 pm
by medelec35
Hi jjw,
It may be just me, but im struggling a bit to know what you want from your description.

What will be good is if you post a list of temperatures, and beside each temperature what action to take.
e.g (made up)
Temp Action
210 Damper 50% ect

You can post excel sheet if easier.

Or post a step by step action as temperature is rising and falling.

Martin

Re: Temperature control

Posted: Sun May 12, 2013 6:32 am
by jjw
Hi Martin,
Please find enclosed excel sheet with temperature controls.

jjw

Re: Temperature control

Posted: Sun May 12, 2013 2:42 pm
by medelec35
My suggestion would be to store the current pri deg position.
Then depending on actual measured temperature calculate the difference required.
E.g Final pos = actual pos - required pos fro given temperature.

E.g if current pos = 60%
pos for new temperature (325 degC) = 40%
This means % has to decrease from 60 - 40 = 20%
Therefore stepper has to rotate counter clockwise 20%

So it won't matter if temperature suddenly jumps or not.
Results in theory should always be correct.
How does that sound?

One thing that puzzles me.
On startup damper always move to its default 80%
If power is removed then restored, damper will again go another 80%.
If damper is on 40% and power is again removed then restored, then damper rotates by 80%

Therefore the damper will never start up in the correct position, unless some type of positional feedback is employed.

Just a thought.

Martin

Re: Temperature control

Posted: Sun May 12, 2013 3:44 pm
by jjw
Hi Martin.

Your suggestion sounds very good can you make an example for my code.

I’ve built non brake power supply so in case of black out the system continues its working properly no prob.

jjw

Re: Temperature control

Posted: Mon May 13, 2013 7:26 am
by medelec35
I will try and post an updated Flowchart a bit later today.

Martin

Re: Temperature control

Posted: Mon May 13, 2013 12:52 pm
by medelec35
Hi jjw.
attached is a flowchart that will hopefully do what you want it to do.

You may need to change 10ma delay within both routines that adjust pri damper depending on temperature.

Modified code is much more efficient since all the macros that was used e.g.

Code: Select all

Prim_Damp_70_10_inc

Are now redundant.

all damp positions are calculated and executed automatically.

Unable to test on hardware.

Martin

Re: Temperature control

Posted: Mon May 13, 2013 3:57 pm
by jjw
Huge thanks to you Martin you have done again great job helping out of my problems. I did some primarily desk tests with an other hardware and the program seems to work properly any much much better than before.....
I will do some field tests maybe next week I will let you the results.

jjw

Re: Temperature control

Posted: Mon May 13, 2013 4:15 pm
by medelec35
You're welcome jjw, so long as it works better.

I would recommend adding just a greater than temperature range, just in case temperature seen is greater than 330 Deg C.
If for example temperature = 305 deg, then suddenly shot up to 330+ valve will stay on 60%.

Martin