MYPIN TA4 PID manual, programming instructions and general PID/SSR info - by request

Discussion in 'Smoker Builds' started by dward51, Sep 15, 2013.

  1. dward51

    dward51 Master of the Pit OTBS Member

    I'm a little late getting to the party on this one, but here we go....

    As to "proportional", the MYPIN will not vary the voltage proportionally to a SSR.  An SSR sees a triggering voltage, which can be within a certain wide range, and it then flips "on" like a mechanical relay, just with no moving parts.  In essence it is a digital switch controlled by a DC triggering voltage.  In your post quoted above you are using a 3 to 32v DC triggered SSR so any voltage between 3 and 32 volts DC will give the same result.  The SSR triggers and the load on the output side is powered (the digital switch closes completing the power circuit).  3 volts does not give any different response than 32 volts so the value of the voltage is irrelevant as long as it is in the acceptable working range of 3 to 32v DC.

    A PID is a three mode controller.  PID stands for proportional-integral-derivative,  and the three values are normally working in concert with each other to perform the desired function.  To just use a controller as  proportional mode only unit defeats the whole purpose of using a PID.  The output is generally either a static relay or a DC triggering voltage in 99% of the MYPIN's I've seen.  There is a way to manually set the proportional value if an auto-tune fails, but again the output is a either a static relay or DC triggering voltage.

    If you are wanting a variable voltage output , it has to be a certain configuration MYPIN (output type code is "D"). Variable voltage will not work in concert with a SSR either. Variable voltage output MYPIN's are not that common, but they are out there. The most common will have SSR triggering output and/or static relay output.  What model do you have? (should be on the sticker - post the full model number and a photo of the sticker would be best).
     
    brumateur likes this.
  2. dward51

    dward51 Master of the Pit OTBS Member

    Well, nevermind.  Looks like you figured it out. 
     
  3. bbryon

    bbryon Newbie

    I have to say I'm impressed with the knowledge of these guys that like to smoke meat. SCR's Triacs, reminds me of my old technician days. There is not a lot of day to day people who know the function and how to test a triac(SSR). This kind of stuff gets me excited.
     
  4. thunderjosh

    thunderjosh Newbie

    Hello I have the mypin ta7 and the issue I'm having is the blower runs almost to my desired temp and starts pulsing at about 4 degrees before, then I way over shoot my desired temp. I would like it to start pulsing around 20 degrees before my desired temp not 4. How do I set this. This is set up on a bbq smoker.
     
  5. Hi guys, 

    I got my Smoker up and running this weekend using the the temp controller.

    Overall I am very impressed with it, It ran +/- 5° throughout the majority of my smoke. (Except when I opened the lid to wrap the ribs, however it settled down rather quickly) 

    Thunderjosh, I am not using the pulse function on mine. When initially heating up I have that issue, however after 20-30min it seems to settle down with the heat fluctuations.

    The ribs turned out great!


    Here is a video I made of it working:



    Thanks for starting this thread Dward51, without all the information you posted I wouldn't have even attempted to make a temp controller!
     
  6. thunderjosh

    thunderjosh Newbie

    How low does your temp get before the fan turns on? At bbq comp I run 225 degrees, I fired my smoker with outside temp of 40 degrees and the fan runs constant till 221 degrees. Then pulses till 225 and shuts off. After it shuts off I hit temps 30-40 degrees over because it stoked the fire so long. I run 20 lbs of lump on start up. If I get it to start pulsing before the destination it may not over shoot as bad. I have a huge back woods clone that I just finished and trying to get tuned. And will the auto tune function work for me. I don't understand how it works.. Thanks Josh[ATTACHMENT=1235]
    [/ATTACHMENT]
     
  7. Hi Thunderjosh,

    On my setup the fan runs constant until desired temperature, I haven't played around with any of the PID functions. (I don't really think I need to)

    The temp usually overshoots by 30ish degrees, however after 15-20min the temp comes down.

    I don't cook in any competitions, so this isn't really a problem for me.

    (I'm sorry if this doesn't help, most of this stuff is over my head.)

    Good luck, and nice smoker! 
     
  8. corkboard

    corkboard Newbie

    Hi everyone,

      I'm doing some research on PIDs to create a small smoker unit (I also plan to double it control an old rice cooker for sous-vide).  At this moment, I only intend to control one heating element at a time - I currently don't have an immediate need to control 2 heating elements.  My dilemma is which model to purchase.  The price difference is minor ($10-$30), but I don't want this project to balloon in costs. 

      I would like to understand the differences between the different MYPIN models, and whether a TA4-SNR/SSR would be good enough. What criteria would make the TA7 more logical?

      

    TA4 vs TA7

    - What is the different between these two models other than size?  The MYPIN manual for wiring show slight differences between the two

    - The TA7 wiring explicitly states "Relay" - does this mean there is a built in relay, or it must still be connected to an external relay? Assumption is that an external SSR is required for high current applications

    SNR, RNR, SSR

    - "S" indicates they output must be connected to a Solid State Relay, correct?

    - "N" indicates none - unused?

    - "R" indicates Relay (basic)

    No matter which model I choose, is it recommended to have at least 1 "S" output and must have an external SSR?  Would a TA4-SSR future proof the use of controlling 2 heating elements?

    Appreciate the help!
     
     
  9. awitte58

    awitte58 Newbie

    From what I gather these are controllers that already have the programming built in and all you do is set it up to do an action at whatever setting you set?

    Does anyone have experience using Arduino boards to read parameters and link them with a Raspberry Pi to control motors/actuators? Obviously for the price you are talking it is cheaper to go this route, but I have access to a lot of boards such as what I listed and would like to throw together some automatic regulating smoker. 

    I also hope to create an app that allows the Arduino boards to notify my phone if temps(of the cook area or firebox) get below a certain number and allow me to change the set temp of the cooking area. 

    Great info tho! Much appreciated! 
     
  10. dward51

    dward51 Master of the Pit OTBS Member

    Hello to all......

    I have not forgotten about this thread nor have I abandoned it.  I was offline for about a month when my motherboard died and I was traveling for work and just did not have time to reconstruct my PC.  Long story made short is the power supply fried, overvoltage arced through the MB and there was a hard crash that also killed my boot drive.  Now that the PC is rebuilt and all my data transferred over, I should be catching back up on my SMF reading this weekend (that's the plan).

    A couple of you have sent me PM's during the time I was down. I think I have now answered them all, but if I missed one, please resend it.

    Thanks
     
  11. dward51,

    Sorry to hear of your computer problems, when they work they are great and when they crash, well I don't even want to think of that!

    I am one of those who contacted you after reading thread after thread on PID's. It was a bit intimidating for me at first (the build) but I am exceptionally pleased with the final product.

    There is going to be a learning curve, I am well aware of that but so was the computer, and we all seem to have overcome that!

    Any way, just wanted to say thanks for your help via PM's from this forum. Guys like you make life more fun for guys like me!

    Dick
     
  12. dward51

    dward51 Master of the Pit OTBS Member

    Nice pit!   As to the overshoot, yes I would expect that.  Generally PID's are used to control electric elements which are instantly "off" when the SSR switches off (or starts to pulse the output as you noticed).  Fire in a charcoal/wood coal pit is not as forgiving.  I would try the autotune function and let it adjust the pit.  Might want to run without meat on the autotune session, but I would go with the normal load of fuel (both type and quantity) that you would use in a competition.   If the autotune can't quite figure out the slope of the way a fire in a pit responds to air flow, then you may need to tweak the settings for the P, the I, or the D (as in PID).  These are all adjustable in a MYPIN or Auber Instruments PID.  Like I said, in most builds, it's not necessary but we are dealing with a fire pit not a heating element.

    I've never had to fiddle with the P, I, or D setting so you will be somewhat in uncharted waters, but I understand the principals involved.  Here is a basic chart of how the values and changes in them would interact on the process being controlled.  (but try the autotune first)
    ParameterRise timeOvershootSettling timeSteady-state errorStability
    [​IMG]DecreaseIncreaseSmall changeDecreaseDegrade
    [​IMG]DecreaseIncreaseIncreaseEliminateDegrade
    [​IMG]Minor changeDecreaseDecreaseNo effect in theoryImprove if [​IMG] small
    Glad it's working. 

    Thanks for the good words.  I'm not "the" expert, but I try to help where I can.....
     
  13. dward51

    dward51 Master of the Pit OTBS Member

    Some additional info on SSR's in general, and how to select the correct model for DC Fans in a "power draft" on a smoker

    There seems to be some confusion about SSR's and what device is needed for what application.  I'm going to take a stab at some basic info here that hopefully will help.

    A SSR is a "Solid State Relay".  This is nothing more than a solid state (think transistor and/or computer chips) device that serves the same function as a mechanical relay.  That is, it switches a power to a load on or off. It does the same job as the good old mechanical or "dry contact" relay which is nothing more than a switch that is actuated by the application or removal of a control voltage.

    The confusion seems to be when we start to talk about "triggering voltages" and "load voltages".

    In most electric smokers, what you have is a PID that uses a SSR to switch a 110v or 220v heating element on and off based on the process temperature (pit temperature).  The confusion starts when you consider the PID outputs a DC triggering voltage to control a AC load voltage.  The low voltage and low amperage output of the PID does not power the load (heating element).  It only causes the SSR to change it's load side state.  An DC to AC SSR requires AC power on the load side of the device to work.  It's not like a DC mechanical relay that will click on and off with nothing connected on the load side of the mechanical relay.  SSR's require power on the load side to work.

    SSR's have an advantage over mechanical relays as there are no moving parts, and no arcing across contacts.  If you have ever had a relay seize up in you car or home AC unit you know what I'm talking about.  In a mechanical relay, as the little contacts approach each other to close the "switch" in the relay, there is always some arcing between the contacts.  This will eventually cause the relay to fail.  The more you switch it on and off, the faster it will fail.  SSR's do not have this problem and are considered to be more reliable that mechanical relays.

    The most common type of SSR we see is the DC to AC (DC triggering voltage from a PID controls an AC load voltage from an AC power source to the heating element or other AC load).  The Fotek 25amp models you see used in so many builds are of this type. 

    However they also make DC to DC SSR's.  These models also use a DC triggering signal but they control (switch on/off) a DC load from a DC power source.  Some of you have been talking about building "power draft" control units where a PID is used to switch a fan on and off like the BBQ Guru units.  Since most of the small fans used in that application are DC powered, you need to have a DC to DC SSR.
    • In the photo below, the SSR on the left is a DC to DC SSR.  This device would use the DC triggering output from a PID to switch a 5 to 60v DC load powered by an external DC power supply (not the PID).
    • The SSR on the right is also a DC to DC SSR, but it has a higher voltage range for the DC load that is being switched.  This one will work with a load side DC power supply of 24 to 220v DC (again from an external DC power supply, and not the PID).
    • In the Fotek models, the "DD" after the amperage rating (in this case 25 amps for both SSR's) signifies this is a DC to DC SSR.  The DC to AC models would show "DA" instead of "DD".

    Here is the most common model we see in smoker builds.  It is a 25 amp, DC to AC SSR (DC triggering voltage from the PID which switches an AC load powered by an external AC power supply).


    Hope this clears up the difference in load types and what type of SSR to use to make a power draft fan controller for a smoker.  (Note I have also see these exact same Fotek SSR's labeled as MYPIN SSR's, and these two seem to be the most common brands used by smoker controller builders).
     
    ruralearl likes this.
  14. dcarch

    dcarch Smoking Fanatic

    A very good explanation of SSRs v.s. mechanical relays.

    I would like to add a couple of important considerations:

    When a mechanical relay fails, the contacts open the electric circuit, no power goes thru. OTOH, when a SSR fails, it shorts the power and it does not shut off.

    Imagine a 1000 watt heater goes on full time and cannot be shut off by the PID. 

    Make sure you consider this unlikely situation, which can be dangerous.

    SSR can be heat sensitive. If it gets very warm when it is on, then you need to have it on a heat sink.

    dcarch
     
  15. Hello dward51,  Thank you for this thread & information contained.  Considering making a draft control vs. Auberin unit.  Would have gotten the wrong ssr (da instead of dd).

    Question:  the fan under consideration is rated at .3a @ 12vdc & the likely pid relay function is rated at 3a @ 250 vac; the instructions (www.globalbuyersstore.com/manual/tm7100r12v.pdf) state that using a ssr will make the controller last longer.  Is this something to be concerned about in this application?  Thank you,  Earl
     
  16. skys

    skys Newbie

    Hi,

    I am using the same MYPIN PID, and need to send 110v to my SSR to switch it, it is a heavy duty 220V SSR controlling an oven.  I cant seem to get 110v to come out of terminal 3&4.  can anyone help?
     
  17. tim scott

    tim scott Newbie

    I got my TA4 PID wired up and it seems that the SSR output stays energized no matter what the led does on the front, I'm thinking I got a bad TA4 any suggestions 
     
  18. controlguy

    controlguy Newbie

    Doesn't work that way.... 3&4 only output a low voltage DC signal.
     
  19. controlguy

    controlguy Newbie

    Has anyone had any issues with the controller not reading temperature accurately over a range? I have two of these controllers that I'm trying out and both have issues with accuracy on temperature. Even after entering an offset, they still both drift off after heating up. Not just a few degrees... Like 15-20 degrees off. I build control systems for a living and have really never ran into an issue like this unless the controller or thermocouple is bad... Having two showing the same issues doesn't seem like just a one-off bad unit. Since you guys seem to be the only folks discussing this controller on the net, I thought I would reach out and see if this is a common issue with this specific manufacturer.
     
  20. dward51

    dward51 Master of the Pit OTBS Member

    Tim,

    The PID only outputs a control signal and does not power a load.  You need a power supply feeding power to a SSR or relay (depends on what variation of the TA4 you have as to which).  The SSR or relay acts as a switch that is controlled by the PID (ie, flipped on or off).  The power supply through that "switch" is what powers your fan, heating element, or whatever else you have.

    ***Also if you have a SSR output PID and you connect a VOM across the load side terminals of a SSR with no load side voltage on the SSR, you will not see the SSR "close" the circuit when the PID triggers it.  It needs a load of some sort and voltage for the SSR to function.  This creates a feedback loop inside the SSR which is needed to make it work.  So don't panic if you have a SSR that does not seem to be working if all you have connected is a meter looking for continuity on the load side of the SSR.  If the LED on the SSR is coming on, try connecting voltage and a small load to the output side and it should work just fine (a small 120v lamp usually works for a PID & SSR that will be controlling a heating element).

    In theory the SSR does the work of a plain old relay, but in actuality there is more to the equation to make the digital circuits inside the SSR work (it needs voltage and a small load to form the feedback loop).

    Here is a diagram I made for another discussion with a forum member to help illustrate how the SSR works.  In his build, he controlled a outlet, but you can change that out for a heating element or other 110v load.  The key thing to remember is no power from the PID crosses over to the load side of a SSR at any time (the PID does not power the load).  There is no true "switch" inside a SSR as it's all digital logic circuits and no mechanical switch.  The concept of how the output side of the SSR performs is best illustrated by a "switch" though.

     
    Last edited: Jun 29, 2014

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