More on the PID

MRH · April 30, 2007, 07:51:36 PM

I never did the autotune on mine and it always seems to hold within a few degrees of where the set point is no matter what temperature I have it set at, once it reaches it. Did I just get lucky? I did start the oautotune but got tired of waiting and just started using it. I have been very happy on how well the control has been, if the weather has been cold or hot when using it.

Mark

Patience · May 02, 2007, 07:50:11 PM

Thanks for the input guys! Now here is another thought. The PID I have has ramp/soak and 2 alarm outputs. I am assuming these alarm relays act as a switch. Current goes into 1 terminal and when the PID's directions tells it to switch, current exits the 2nd terminal to run just about anything you want. Does that mean I can hook a hot 120v wire in, and then feed the out terminal to the smoke generator motor? I don't know the specs of the input/output of the alarm relays yet, but I'm hoping that will work.

In other words, after say 2 hours of 120 deg. drying time, the PID ramps up to 140 deg. and when it hits 140 degrees, the alarm relay completes the circuit to the smoke generator motor and it starts smoking after a cycle or two of 20 minutes to feed the waiting pucks. After a programmed time you can tell the alarm relay to shut off, cutting the smoke. This would kind of be acting like the smoke generator switch Bubbagump put into his setup. Instead of a manual switch, the alarm switch will automatically start it and turn it off after a specified time. Am I climbing too far out on the limb of high thought here?

Don't think I'm being too lazy, there is a method to my madness as well as madness to my methods. Somebody with electrical experience please let me know if this is a go.

Have, Patience

Arcs_n_Sparks · May 02, 2007, 08:04:18 PM

Patience,

I do not have a ramp/soak PID with alarms. However, if your alarm function is a relay closure, then you can do what you propose (assuming the relay contacts can handle the load of the smoke generator). It is unclear to me how you time out the alarm condition and drop out the smoke generator.

If the alarm relay will not handle the load, it is pretty easy to wire in a relay that would take care of it.

Have you seen Mr. Walleye's setup using Schedule 80 PVC pipe?

Arcs_n_Sparks

Patience · May 02, 2007, 09:10:51 PM

Arc,

I have not seen the use of PVC, though I have read a few threads from Mr. Walleye when he was having problems with his SSR. Since then, searching under various subjects, your posts frequent many of them, thanks for sharing your know hows! From what I gather, the programable PIDs have commands to turn alarms on and off. 1=Alarm 1 on, 2 = alarm 2 on, 3 = alarm 1 and 2 on, 5 = alarm 1 off. etc.

If I understand it correctly it would take 3 commands to process the smoke. The smoke command turns the alarm relay on when temp reaches X degrees. The next command will hold X degrees for Y minutes while alarm is still on, aka smoking. After Y minutes the program goes to the next step, which will be the smoke off command. My only hang up is, once the relay is triggered for X degrees, what happens if X falls 10 degrees for some reason, will the alarm cut off, or will it wait for the alarm off command. Once I get the entire manual, if I post the specs of the alarm relays can you help figure out if I can run power through the terminals? ??? My head hurts, I'm going to bed!

I could just be talking out my ^&&, but it sounds good to me! :-\

Thanks in advance!

Arcs_n_Sparks · May 02, 2007, 09:16:22 PM

Quote from: Patience on May 02, 2007, 09:10:51 PM
Once I get the entire manual, if I post the specs of the alarm relays can you help figure out if I can run power through the terminals?

Yes, and I am sure there are others here that can help you out as well.

Quote from: Patience on May 02, 2007, 09:10:51 PM
My head hurts, I'm going to bed!

Take two Jack and e-mail me in the morning. :D :D :D

Patience · May 03, 2007, 04:02:11 AM

I took two aspirins, alcohol and I don't like each other. ;D Anyhow, I did more thinking on your question. I'll just have to wait until I get the book and try and figure things out.

The alarm output says 120VAC/3amp, I have no idea what the puck advance motor pulls. It looks like I can create a command in one of the 30 available steps to shut alarm on/off at will, rather than have it triggered by temperature. It would of course be triggered by temperature and shut off with a command. I don't think you can shut the relay off other than letting the temp drop below the trigger temp minus the deviation, other than the simple off command.

Have, Patience

Mr Walleye · May 03, 2007, 12:35:57 PM

They used to have .pdf versions of their manuals available but I don't see them on their web site now. You should shoot him an email. I'm sure if he has the manual in .pdf format he will sent it to you. That way you can study it before it arrives.

Mike

Patience · May 03, 2007, 01:35:46 PM

Thanks 'eye!

I got the pdf files, he emailed me back so fast, I thought it was an error return mail for a wrong address. Anyway, it looks like the ramp/soak PID Auber sells does have on/off commands seperate from temperature triggered alarms. I think this will work as I have explained earlier by completing the puck advance motor circuit. I still would need the programable PID to automatically step up the set temp over several hours as some of the recipes call for. As far as the automatic smoke idea, I havn't checked my Bradley, but somebody in this forum says they have to hit the advance button atleast once before it will advance every 20 minutes. If that is the case, this idea will not work as easy as I thought. I have always hit the advance button so I don't know if the motor will advance or not until the button is pushed atleast once. Any thoughts?

I was just thinking also, the damned damper still needs to be closed half when the smoke starts. I will have to sweet talk the wife into running out and turning it if I'm at work. I think as long as all she has to do is change the water and turn the damper, we're in business. I'll have to turn on the charm the day (and especially night) before smoke day! ::)

I have been reading this forum everynight and I am chomping at the bit to do all this stuff. I think I'll have to just take it a step at a time though, get the PID working, find a good tune and get things consistent before moving onto the autosmoke thing. Thanks for everybodys help!

Mr Walleye · May 03, 2007, 02:37:12 PM

It sounds like you have the OBS? If so I'm not sure about how the advace works because I have the DBS. I'm sure someone will chime in.

Keep us up to date on your projects. I'm always interested in tinkerin'! ;D

Mike

Arcs_n_Sparks · May 03, 2007, 05:50:27 PM

Quote from: Patience on May 03, 2007, 01:35:46 PM
I was just thinking also, the damned damper still needs to be closed half when the smoke starts. I will have to sweet talk the wife into running out and turning it if I'm at work.

Sounds like it is time to design a stepper motor arrangement for vent control... 8)

Got a few in the garage to play with. Thank goodness they are next to the adult beverage refrigerator.

smokin stu · May 05, 2007, 04:26:47 PM

Patience, I have no clue what the heck your'e talking about ??? but that's okay, I think I don't want to trouble my fragile mind right now :) by the way, plugged my beer fridge in this aft and have been diligently testing the product for optimal temperature.... fallen soldiers all about me, but I'll get it done.

I have an OBS, a PID, autotuned it under load (a butt fours hours in), and have the BS stored away in a BS shack I built and I use a Maverick ET-73. It runs as good as I can imagine. I try and have a beer every time I need to rend to the BS so whatever you plan on doing, make sure you need to tend it occasionally. :D

smokin stu · May 05, 2007, 04:28:22 PM

By the by, FTC'ing really takes whatever you've done and takes it another level entirely.

Patience · May 05, 2007, 06:44:48 PM

If I drank a bev everytime I tended the unmodified OBS, you'd find me puking behind the doghouse. Last time I drank a beer was the half that was left over after making brats one night back in 2003 (no kidding!).

I like the idea of the cabinet. That will tame the swinging Michigan weather and thats definitly next on my list. What my final plan is, to be 20 miles out into Lake Michigan trolling for salmon and tell the guys while looking at my watch, "Well boys, temps up to 140 and holding, and the smoke is starting to roll right about now" all the wife has to do is change the water and turn the damper. Next year I think I'll make a go at automating those as well....we'll see! :)

Oh yea, FTC will still be final step. In fact, if I get good enough at anticipating time to target temp of meat, I will actually incorporate atleast 2 hours of FTC into the final equation.

Listen to me, I havn't even been delivered all my PID project parts yet!!!!

West Coast Kansan · May 05, 2007, 08:47:35 PM

;) When you do get the wife automated please post the results ... saw a movie about that once but still have not get in figured out ;D

Arcs_n_Sparks · May 06, 2007, 07:08:37 PM

Quote from: Arcs_n_Sparks on May 03, 2007, 05:50:27 PM
Quote from: Patience on May 03, 2007, 01:35:46 PM
I was just thinking also, the damned damper still needs to be closed half when the smoke starts. I will have to sweet talk the wife into running out and turning it if I'm at work.

Sounds like it is time to design a stepper motor arrangement for vent control... 8)

Got a few in the garage to play with. Thank goodness they are next to the adult beverage refrigerator.

Okay, doing design work next to the adult beverage refrigerator was not a great idea this time around. :o

Ended up letting the smoke out of one of the stepper drive I.C.s when I "fired up" the circuit. This is not the smoke you want to see. However, the beef sticks I made today came out great, so I came out even for the day.

Arcs_n_Sparks