UDS Controller

[Tremolo]

Finished building a controller for my UDS. PID controller using simple on/off with a 3 degree dead band. Controller driving a 40mm 7.5 cfm fan. Also added a second switch so I can turn the fan off when the lid is removed. Hope to do a test run this weekend.





Sent from my DROIDX using Tapatalk

[nickelmore]

Looks cool, are you versed with PID, I am having a challenge setting the "dead band"

[Tremolo]

Which controller are you using?

Sent from my DROIDX using Tapatalk

[DDave]

Looking forward to hearing about the test run.

Dave

[Tremolo]

Picked up 3 slabs of spares not sure if I will be trying it out on saturday or sunday. Will have to see what the weather looks like.

Sent from my DROIDX using Tapatalk

[Mark R]

Cool we waiting to read!

[Tremolo]

Nickelmore if your using the auber syl-1612 with SSR go into setup and enter code 0089. Set outy to 3. If not using an SSR set outy to 4. This sets the controller to on/off control output. Next set hy to whatever you want your dead band. I set mine to 3. Meaning the fan will not turn on unless it is 3 degrees below your set value.

The dead band feature is only enabled in on/off mode. It is disabled in PID modes.

Let me know if you have any questions.

Sent from my DROIDX using Tapatalk

[DDave]

Nickelmore if your using the auber syl-1612 with SSR go into setup and enter code 0089. Set outy to 3. If not using an SSR set outy to 4. This sets the controller to on/off control output. Next set hy to whatever you want your dead band. I set mine to 3. Meaning the fan will not turn on unless it is 3 degrees below your set value.

The dead band feature is only enabled in on/off mode. It is disabled in PID modes.

If you're using on/off mode then don't you lose the benefit of the PID -- mainly the ability to determine the appropriate output depending on set point/control point delta and the time away from the set point? I would think that just turning the fan on full blast when your 3° below your set point would cause a UDS to cycle wildly out of control.

My Auber uses the SYL-1613 and the PID parameter settings are available on their website.
http://auberins.com/images/Manual/SY...0manual-v1.pdf

Page 2 has the relevant stuff.

More often than not when mine is at or around the setpoint the fan is just pulsing occasionally.

I imagine the settings would be a good start for a similar application.

Just a thought.

Dave

[Tremolo]

Will a dc fan operate at variable speeds without PWM?

Sent from my DROIDX using Tapatalk

[DDave]

Will a dc fan operate at variable speeds without PWM?

On my Auber the fan is not variable speed. The PID loop controls the length of time that it runs during a 7 second Cycle Rate period.
The Cycle Rate is one of the PID parameter settings on the 1613. I'm not sure if it is on the 1612.

So in essence it works something like this . . .

If the PID output value is calculated to be 100% then it runs for 7 seconds every 7 seconds. (7 on and 0 off or on all the time)

If the PID output value is calculated to be 50% then it runs for 3.5 seconds every 7 seconds. (3.5 on and 3.5 off)

If the PID output value is calculated to be 25% then it runs for 1.75 seconds every 7 seconds. (1.75 on and 5.25 off)

If the PID output value is calculated to be 10% then it runs for .7 seconds every 7 seconds. (.7 on and 6.3 off)

If the PID output value is calculated to be 0% then it is off.

Kind of a, IMHO, non-elegant way to get variable speed behavior out of a non-variable speed fan. It seems to work pretty well though.

Dave

[Tremolo]

I guess it really on matters with size of your fan. You wouldnt want full on with an oversized fan because it will over shoot. A smaller fan I dont think would matter much. I used a 7.5 cfm fan but with the 1.5" x .75" reducer it is really restricting the flow. I am thinking I will need one of my other vents part open but we shall see if the weather clears up this weekend. If it doesnt work I can upgrade to a 10 or 12 cfm fan.

What size fan are you using? Got any pics of your setup?



Sent from my DROIDX using Tapatalk

[DDave]

What size fan are you using?

20 CFM

Got any pics of your setup?

I cheated and bought the system prebuilt.
http://www.auberins.com/index.php?ma...roducts_id=205

Here are a couple of threads on it.
http://www.smoked-meat.com/forum/showthread.php?t=14743

And here is a graph of one of its runs from this thread.
http://www.smoked-meat.com/forum/showthread.php?t=16810



In looking at the documentaton for the 1612 (B) controller, it looks like it has the same PID settings available as the 1613. If the on/off mode doesn't give you the control you are seeking, it may be worth a try to use the PID settings from the link that I posted and give it a whirl.

Some things I have noticed with mine -- on warmup it tends to overshoot the setpoint by about 20°. So now if I want to smoke at 240°, I'll set it to 220° or so to warm up then increase the set point after the fan has backed off.

Also it seems to work better if there is something between the charcoal basket and the sensor. I use a deflector plate but even a piece of aluminum foil or something to shield the thermocouple from the direct heat seems to work well. Not because it can't handle the heat but because the thermocouple is so sensitive that it seems to chase the setpoint if it is subjected to direct heating verus somewhat indirect.

Hope this helps.

Looking forward to seeing your test run.

Dave

[DDave]

So . . . what is the status?

Inquiring minds want to know.

Dave

[Tremolo]

Have not tested it yet. Had a lot of running around to do today. I will start the ribs tomorrow late morning or early afternoon.

Wish I had a data logger. Guess I will have to go old school with a pen and paper.



Sent from my DROIDX using Tapatalk

[Tremolo]

Well I tested out the controller yesterday and found the my fan is under powered. I kinda knew this would be a problem before I even started. The 1 1/2" x 3/4" reducer is resticting air flow. Had to have one 3/4"all the way open and my valve set to 1/4 open. Once i got.the valve position set it held decent getting a 3-5 degree over shoot and temp would drop about 2 degrees below the beadband.

The current fan I have is 7.5 cfm. I have seen 28 cfm fans that I am thinking about getting. I am hoping that a larger fan will push more air through the restiction.

Sent from my DROIDX using Tapatalk