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Step by Step Guide - Install PID in a Silvia.

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  • #16
    Re: Step by Step Guide - Install PID in a Silvia.

    Originally posted by 6470640505340 link=1246334170/14#14 date=1249538025
    Interested to know if anyone has seen PID temperature reading errors.
    Have a look at this thread on CoffeeGeek.com.  I think it addresses the issues you brought up.

    http://www.coffeegeek.com/forums/espresso/machinemods/434915

    Jim

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    • #17
      Re: Step by Step Guide - Install PID in a Silvia.

      Originally posted by 495D492828190 link=1246334170/14#14 date=1249538025
      Other possibilities are the thermocouple junction repair with ordinary Tin/Lead solder maybe wrong (dont know if the bead has to be silver soldered or something else special) ...  
      It is very difficult to get most solders to wet the alloys in type K wire.  Best way to make the junction is by welding the wires directly together.  All of the commercially made bead sensors Ive personally seen are made by welding.

      If you are making (or repairing) your own, and have somehow misplaced your t/c welder, then tightly twisting the wires together will probably work as well as solder for a type K.

      Jim



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      • #18
        Re: Step by Step Guide - Install PID in a Silvia.

        Originally posted by 5246523333020 link=1246334170/14#14 date=1249538025
        they dont bother to temperature compensate in a cheap Chinese PID
        Hey Garry,
        If you check out the instructions you got with your PID, you will find the temp error offset variable in the settings menu, id prolly double check your DMM reading though, as you may be wasting your time, it could be the DMM, and besides, the temp really is irrelevant, its all just an indication, you will have to pull shots to find where the SP needs to be, it will simple hold it there. Hope your having luck tuning the PID, it can be a little frustrating at times but you will find those perfect settings keep at it mate and keep us posted,

        Ps ill be updating the guide soon, thanks for the input, and i must apologise if i sounded a little nasty in my pm, i re-read it last night,and....um :-[ sorry mate, had some personal issues with my dad and i wasnt in the happiest of moods, genuinely sorry if i was rude....
        cheers
        wsullly

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        • #19
          Re: Step by Step Guide - Install PID in a Silvia.

          Just so i get a feel for how the guide is helping/not helping fello CSnobs,
          Cheers Guys and Gals
          Wsully

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          • #20
            Re: Step by Step Guide - Install PID in a Silvia.

            Keep up the good work Wsully....
            Its great that you can find an alternative and share it with us.
            Im keen to do it.....Just waiting for the revised edition ...... and finding time to attempt it :-/

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            • #21
              Re: Step by Step Guide - Install PID in a Silvia.

              Originally posted by 091D096868590 link=1246334170/14#14 date=1249538025
              Just put another thermocouple into Silvia at the same location as the PIDs thermocouple so we can capture readings on the laptop. With Silvia cold Ive noticed the PID reading a few degrees low compared to one of my Digital Multimeters. Maybe a problem with the reference junctions not being correct so leaving things to settle over the next couple of hours and Ill recheck with a couple of different DMMs.
              Noooooo.... not the "my thermocouples reading different from your thermocouple" debate! (just wanted to get in B4 AM weighs in with a reprise of "cheap TC == horrible errors" so no use comparing 2 or more of the wretched things...

              And now Im told that every connection is a "junction", so lets just give it up right there already...

              Currently more interested in the apparent instability of the DMM reading compared to the PID -- wonder what thats about :-?

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              • #22
                Re: Step by Step Guide - Install PID in a Silvia.

                what in gods name is a PID ! ?

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                • #23
                  Re: Step by Step Guide - Install PID in a Silvia.

                  Originally posted by 5F444552131B19132B0 link=1246334170/21#21 date=1253101677
                  what in gods name is a PID ! ?
                  Painfully Ignorant Decaf ;D ;D


                  Sorry..

                  Go here - http://en.wikipedia.org/wiki/PID_controller

                  Comment


                  • #24
                    Re: Step by Step Guide - Install PID in a Silvia.

                    Originally posted by 537C7577605F737C7375777F777C66120 link=1246334170/22#22 date=1253101798
                    Originally posted by 5F444552131B19132B0 link=1246334170/21#21 date=1253101677
                    what in gods name is a PID ! ?
                    Painfully Ignorant Decaf    ;D   ;D


                    Sorry..

                    Go here -  http://en.wikipedia.org/wiki/PID_controller
                    Sorry too,

                    It depends--where I work it stands for Pelvic Inflammatory Disease. I could never work out why youd want to install it in a woman named Silvia.

                    Greg

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                    • #25
                      Re: Step by Step Guide - Install PID in a Silvia.

                      Tony,
                      a PID is a device we use to stabilize the temperature in machines that dont do it well enough on their own, as you might know, shot taste can alter dramatically =/- 1C and when a silvia has a temp brew range of between 86 - 116 degrees, it needs to be harnessed, this is what a PID does, it cycles the boiler to maintain a specified temperature.

                      cheers
                      warren

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                      • #26
                        Re: Step by Step Guide - Install PID in a Silvia.

                        Originally posted by 342F2E3978707278400 link=1246334170/21#21 date=1253101677
                        what in gods name is a PID ! ?
                        It refers to a controller for a process, specifically each letter has meaning to how the controller achieves its control, and how it reacts to changes.


                        Some control terms:

                        SP is set point, in this case the temperature wanted at the boiler.

                        PV is process variable, the actual temperature of the boiler.

                        P is Proportional, so the output change is in proportion to the input change, as the output to the element is digital, either on or off, it pulses the element on and off to achieve a sort of proportional output.

                        I is integral, a calculus term for the area between a curve and the zero or set point.

                        It is used in controllers to remove offset, where the stable condition of  proportional only controller is not on the set point or the desired amount, in this case, temperature.

                        D is derivative, another calculus term, but this time looking at the rate of change (the slope of the curve) of the input.

                        This makes the controller settle down to the set point much quicker than a P or PI controller.
                        I see this on my Sylvia in the "heater on" light stopping pulsing while the indicated temperature was below the set point.



                        You need P in all controllers, but modern controllers are PD while older (20 years ago) controllers were PI, if not using full PID.
                        To make a controller a PI or PD, the I or D setting is set at zero.
                        On some slow changing systems PID isnt always needed.

                        A correctly tuned controller should settle down after 3 and a half oscillation.

                        So it would be better, or at least more accurate, to call it a PID controller, or just a controller, as this makes the purpose of the device more clear, IMHO anyway.

                        Hope this helps rather than confuses.

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                        • #27
                          Re: Step by Step Guide - Install PID in a Silvia.

                          Great explanation Andy... [smiley=tekst-toppie.gif]

                          That will be a big help to a lot of people wondering what on earth this PID word means. I much prefer to use the term Controller also, as it better describes what the device does....

                          Mal.

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                          • #28
                            Re: Step by Step Guide - Install PID in a Silvia.

                            sorry if this is not the right thread.

                            What model of PID have you guys got please. I need the full model number as i have access to a watlow account.

                            cheers in advance
                            forrie

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                            • #29
                              Re: Step by Step Guide - Install PID in a Silvia.

                              forrie - pretty much any PID controller will work irrespective of its actual branding. The only real difference is how you program them. You dont need one with ramp/soak, just simple set-point control.

                              Go for the smallest physical model - a 1/32nd DIN formfactor. Plus choose one with SSR outputs, rather than relay outputs (the difference is that the SSR will switch on/off on a mSec basis, but the relay one will be about 2seconds on/off minimum).

                              While none of my Watlow controllers are steam powered, none of them are current models - so I cant really give a part# that you could purchase in 2011..

                              /Kevin

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                              • #30
                                Re: Step by Step Guide - Install PID in a Silvia.

                                Could give you auber parts, or sestos, but not Watlow. As KJM says, pretty much any PID will do.  Dual set point might be nice, but not critical.

                                Edit:
                                PID must be able to drive an SSR, internal relay wont cope.

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