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  • motorized potentiometer

    so i am looking potentiometers and would love to be able to have the option of either sending an analog signal to a fb from my computer or by a dial on my dash.

    I'd have the dial on the dash with a markings from say 1-10. when i turn the dial to '4', the computer would update it's display to '4' and my hydrofoil would go to position '4' via fusionbrain. but.. say i was in front of my tablet (win7 running my front end, fusion brain connected to the usb port) and i wanted to adjust the hydrofoil to '10'. well i'd select '10' on the tablet, the foil would move to 10.... but the pot would be out of sync.

    it seems that the motorized pots just have a dc motor on them... are there any analog potentiometers with a servo or analog input that would turn the pot to a specific position?
    New System in progress:
    M10k
    Phaze TD1500 ~> Dynaudio MD130
    Phaze TD1500 ~> Seas g18rnx/p
    Zapco Ref 500.1 ~ 12" tc-9
    Behringer DCX2496 ~ Envision Electronics psu
    Transflective Xenarc

    My Car Pc Install
    My Boat Pc worklog

  • #2
    i assume you have seen this site:
    http://www.p3america.com/motorized_p...eters_text.htm

    this model appears to be completely analog:
    http://www.p3america.com/pp/bs275.htm

    the only thing i am a little worried about is the marine usage..
    My OLD 2001 Mitsubishi Eclipse GT:
    "The Project That Never Ended, until it did"


    next project? subaru brz
    carpc undecided

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    • #3
      i saw this but i 'assumed' these were very expensive seeing how finding them for sale online isn't that easy. and i really didn't see a lot of information about them either. i dont want to break the bank on this feature. if worst comes to worst i could just have an led indicator of some sort to tell me what position the foil is in.
      New System in progress:
      M10k
      Phaze TD1500 ~> Dynaudio MD130
      Phaze TD1500 ~> Seas g18rnx/p
      Zapco Ref 500.1 ~ 12" tc-9
      Behringer DCX2496 ~ Envision Electronics psu
      Transflective Xenarc

      My Car Pc Install
      My Boat Pc worklog

      Comment


      • #4
        yeah, i really didn't look for pricing info. though i agree-- there is no way all that planetary gearing and digital circuit design is very cheap..

        ok, take 2- the diy alternative:

        some motors with planetary gearing for slow speed:
        http://www.goldmine-elec-products.co...?number=G16300

        ..and that is as far as i can get-- i don't seem to be able to locate any potentiometers that have shafts passing to both sides of the unit--like what would be needed to duplicate their design..


        and i lied..

        it turns out, you can find anything on ebay:
        http://cgi.ebay.com/ALPS-GENUINE-MOT...item2a0b3c53b8

        search results:
        http://shop.ebay.com/i.html?_nkw=mot...iometer&_rdc=1
        My OLD 2001 Mitsubishi Eclipse GT:
        "The Project That Never Ended, until it did"


        next project? subaru brz
        carpc undecided

        Comment


        • #5
          [edit: i was typing this up before i saw your post, but that is the type of motorized pot i am referring to in my post:]

          hmmm... i could have the fb control the pot... and in turn the output of the pot be read by the fb?

          i plan on setting it up like this:
          the hydrofoil is rotated by a linear actuator. i'll have the fb control the actuator via a set of relays
          a hall effect ic will detect the angular position of the hydrofoil arm. this will give an analog output and be read by the fb which will tell the computer it's position (and therefore when to stop).
          when i enter a certain value in riderunner; hopefully, based on the current reading from the hall effect it'll retract or extend the actuator until it receives the desired value from the hall ic.


          sooo... would it work to loop a 'dumb' motor driven potentiometer into the mix?

          computer control would look like this: turn the pot via 12v motor leads (fb controlled). when the pot reaches a value (lets say value of '2v') the fb will turn off the relays controlling the pot's motor. the fb will also move the actuators till it gets a similar reading from the hall ic.
          Last edited by scott_fx; 08-05-2011, 12:40 AM.
          New System in progress:
          M10k
          Phaze TD1500 ~> Dynaudio MD130
          Phaze TD1500 ~> Seas g18rnx/p
          Zapco Ref 500.1 ~ 12" tc-9
          Behringer DCX2496 ~ Envision Electronics psu
          Transflective Xenarc

          My Car Pc Install
          My Boat Pc worklog

          Comment


          • #6
            so doing some more research, i came across this website:
            http://www.cibomahto.com/2008/02/thi...-input-device/

            i wonder if i can leave it in the off state until the foil moves into position then the fb would power up the servo and move it to the correct position?
            New System in progress:
            M10k
            Phaze TD1500 ~> Dynaudio MD130
            Phaze TD1500 ~> Seas g18rnx/p
            Zapco Ref 500.1 ~ 12" tc-9
            Behringer DCX2496 ~ Envision Electronics psu
            Transflective Xenarc

            My Car Pc Install
            My Boat Pc worklog

            Comment


            • #7
              maybe i don't understand servos enough, but if the servo is not powered, where does the voltage come from?
              My OLD 2001 Mitsubishi Eclipse GT:
              "The Project That Never Ended, until it did"


              next project? subaru brz
              carpc undecided

              Comment


              • #8
                well i would only be using the internal pot.

                the more i think about this. all i really need is the motor, gears and pot from the servo. i dont need the 'brains' as long as i can control it via fusion brain. it's basically just a dc motor, a pot and a gearbox right?
                New System in progress:
                M10k
                Phaze TD1500 ~> Dynaudio MD130
                Phaze TD1500 ~> Seas g18rnx/p
                Zapco Ref 500.1 ~ 12" tc-9
                Behringer DCX2496 ~ Envision Electronics psu
                Transflective Xenarc

                My Car Pc Install
                My Boat Pc worklog

                Comment


                • #9
                  yes, you just described a servo.

                  weather this helps you or not, i need to break this down to the needed components:

                  well, you absolutely need a pot to control the wedge in certain amounts...

                  you need a motor to allow you to adjust the pot remotely.

                  with a standard motor, you would def need a gearbox due to the very large steps between motor rotations to allow for a more precise control of the pot-esp so it doesn't just snap between '1' and '10'.
                  you could use a stepper motor without a gearbox-- that could have very fine steps, and would not need a gearbox, though controlling it is a little more complex..

                  the problem becomes attaching the motor to the pot.

                  i don't see any easy way to do this with most pots, as they only have a input shaft on one side.


                  -- new idea--
                  what if you would install a standard pot directly connected to a gearbox/motor, or stepper motor, and then control the steps from a touchscreen? that way, you are digitally controlling the wedge steps, which would allow either local or remote adjustment..


                  oh wait, the entire reason for the physical knob is so you can use that for local adjustments, and so you don't need one other thing to display on the screen. right?

                  if you could do it digitally, then there would not be any need for a knob at all...

                  (why am i the only one adding to this--i am sure someone else has come across something that should work for this situation)
                  My OLD 2001 Mitsubishi Eclipse GT:
                  "The Project That Never Ended, until it did"


                  next project? subaru brz
                  carpc undecided

                  Comment


                  • #10
                    im sorry, my above post was a bit misleading. i was saying that i need the pot, gearbox and motor... from the servo.

                    I want the knob for local adjustments and an alternative to using the computer. My current version of this setup is tablet based (win7). I have the tablet connected to network usb hub via a wifi router. This leave the tablet completely unteathered and can be anywhere on the boat. for instance: say my g/f wants to choose some music while she's at the bow of the boat. If i wanted to adjust the foil, it would be great to just turn a dial without having to grab the tablet. On the other hand, i am also going to have a 'preset' skin that will fill the ballasts, and set the foil position (possibly even set the cruise control speed). With that in mind; if i hit the preset from the tablet, the knob would be out of sync.

                    my options would to either have a continuous rotating rotary encoder and then some sort of digital dispaly.
                    -or-
                    a knob that would self adjust based on the foil's position

                    i think the latter is cooler.



                    I'm thinking that I could bypass the 'brains' in the servo and wire up the fb to the servo's internal dc motor and pot. I would then attach a knob to the servo shaft. when i turn the knob; it would turn the pot, giving the fb an analog input. If i set the foil's position digital from the tablet, the fb would spins the motor and obviously it would in turn also spin the knob and pot.

                    do you think that would work?
                    New System in progress:
                    M10k
                    Phaze TD1500 ~> Dynaudio MD130
                    Phaze TD1500 ~> Seas g18rnx/p
                    Zapco Ref 500.1 ~ 12" tc-9
                    Behringer DCX2496 ~ Envision Electronics psu
                    Transflective Xenarc

                    My Car Pc Install
                    My Boat Pc worklog

                    Comment


                    • #11
                      Originally posted by scott_fx View Post
                      im sorry, my above post was a bit misleading. i was saying that i need the pot, gearbox and motor... from the servo.
                      i see, it is now as clear as mud.. to many ideas

                      Originally posted by scott_fx View Post
                      I want the knob for local adjustments and an alternative to using the computer. My current version of this setup is tablet based (win7). I have the tablet connected to network usb hub via a wifi router. This leave the tablet completely unteathered and can be anywhere on the boat. for instance: say my g/f wants to choose some music while she's at the bow of the boat. If i wanted to adjust the foil, it would be great to just turn a dial without having to grab the tablet. On the other hand, i am also going to have a 'preset' skin that will fill the ballasts, and set the foil position (possibly even set the cruise control speed). With that in mind; if i hit the preset from the tablet, the knob would be out of sync.
                      pretty much how i was thinking you wanted it..

                      Originally posted by scott_fx View Post
                      my options would to either have a continuous rotating rotary encoder and then some sort of digital display.
                      this was my next thought-- not the digital display, just to use a rotary encoder to connect to the pc, and update the pc screen.

                      Originally posted by scott_fx View Post
                      -or-
                      a knob that would self adjust based on the foil's position
                      ..which is why you were considering the servo idea. i'm starting to catch on..

                      Originally posted by scott_fx View Post
                      i think the latter is cooler.
                      agreed. you could also use a argument that it is easier to see where a knob is set then to look at a pc screen, or that the tactile feel of a knob makes adjustments require less visual attention


                      Originally posted by scott_fx View Post
                      I'm thinking that I could bypass the 'brains' in the servo and wire up the fb to the servo's internal dc motor and pot. I would then attach a knob to the servo shaft. when i turn the knob; it would turn the pot, giving the fb an analog input. If i set the foil's position digital from the tablet, the fb would spins the motor and obviously it would in turn also spin the knob and pot.

                      do you think that would work?

                      ok, so i see where your going..

                      i have my doubts.

                      here's the problem i see--i own 3 'premium' rc vehicles(have a total of 5-- 2 of 5 have built-in linear servos that you could never move in this manner):

                      servos connected to a standard knob are going to be very hard to turn-- the gear reduction in them means that you need a decent amount of force.. you would need a knob similar to this:
                      http://search.digikey.com/scripts/Dk...me=450-1728-ND

                      smaller servo's are easier to move, but those can also be a larger problem because the individual teeth are smaller, and they are not designed for constant exterior force--so they are easier to break--at least with plastic versions, like my eflight ds75's..

                      the second problem is that servo's are not exactly precise when moving by external force-- once you start to get a servo moving, without a large lever on it, it requires a lot of precision to move it to a certain spot within it's travel. so you might be able to move it from '1' no problem, but to predictably stop at '4' requires a lot of concentration..

                      in a perfect world, you could just add a electronic clutch that would disengage the motor and partial gear-train from the knob/pot to get a free-er moving setup(so the clutch would engage whenever the motor was powered, and disengage as soon as the motor de-energises), though, i have never heard of that before.. and the other problem with adding it is that there is no way you could use the stock servo case..

                      if your interested, i would need to dig them up, but i have 3 metal geared JR servo's i could donate to the project(i've got no use for them..):
                      http://www.amazon.com/241-Micro-Serv.../dp/B000BMBUVK

                      they were too slow for my heli, and they are analog, so they didn't work right(the other servo on that bird is digital, so it led to a twitch issue)...
                      My OLD 2001 Mitsubishi Eclipse GT:
                      "The Project That Never Ended, until it did"


                      next project? subaru brz
                      carpc undecided

                      Comment


                      • #12
                        so talking about the clutch just made me think about those motorized alps pots. i think we just went full circle. if i'm taking out the 'brains' out of the servo, isn't it basically functioning the same way as the motorized pot? i can get rotational data from the pot itself and control the motor position that way.
                        New System in progress:
                        M10k
                        Phaze TD1500 ~> Dynaudio MD130
                        Phaze TD1500 ~> Seas g18rnx/p
                        Zapco Ref 500.1 ~ 12" tc-9
                        Behringer DCX2496 ~ Envision Electronics psu
                        Transflective Xenarc

                        My Car Pc Install
                        My Boat Pc worklog

                        Comment


                        • #13
                          lol. pretty much... the difference is the shipping-- the servo option is as close as the nearest hobby shop, the pot is 15-30 days away..
                          My OLD 2001 Mitsubishi Eclipse GT:
                          "The Project That Never Ended, until it did"


                          next project? subaru brz
                          carpc undecided

                          Comment

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