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Newbie Furnituremaker needs help with actuating mechanisms

Discussion in 'Robotics & Mechatronics' started by skegemog, Aug 6, 2012.

  1. skegemog

    skegemog New Member

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    Hi everybody, I am new to this board but I hope you won't hold it against me. I am a furniture maker of many years experience and have a pretty basic understanding of electrical circuits but we have a project right now that is beyond my experience.

    Essentially we have built a sideboard that conceals a flat screen TV. When the customer wants to watch the TV we have put together a mechanism that moves a panel out of the way so that the TV, which is mounted on a commercial lift mechanism, can rise out of the console into view.

    The mechanism that moves the panel is powered by a Pittman gear motor rated at 19.1 volts and its travel is limited by micro switches.

    The lift mechanism has a power brick (that produces 30 volts according to my multimeter) which connects to the drive motor through a control box that is operated by a little hand held wireless clicker (not IR, I'm guessing some kind of radio transmitter) The control box has a few relays in it and a printed circuit board. the cable that connects it two the lift motor has a 6 pin connector. I spent a little time trying to figure out what the connections between the control box and the drive motor might be and it seems that two of the pins may be the power supply for the motor. I made this determination because when the clicker is manipulated the readout on those two pins goes from 0 to 30 vdc to -30 vdc as one would want to energize the motor in either direction.

    This is the extent of what I know. What I would like to have happen is that the clicker activate both the panel mechanism and the lift mechanism. What would be even better would be if I could use the same power supply for both but I realize that may be beyond it's capability. So I guess what I am asking is: is there a way to hack the control box so it sends power to my panel mechanism or at least operates a relay to switch power from another power supply to the panel mechanism? OR is there away to setup another receiver and necessary circuitry to power the panel mechanism but in a way that is synchronous with the lift?

    Any input would be much appreciated, thanks!!
     
  2. alec_t

    alec_t Well-Known Member Most Helpful Member

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    The pins that go 30-0-30 seem the obvious place to take off a signal for the panel mechanism. Unless you know the power brick's rating has enough in reserve to power the panel mech in addition it would be wise to use a separate supply for that, as you recognise.
    Will a delay be needed between actuating the panel mech and the lift mech?
    Is there any prospect of just mechanically linking the two mechanisms instead of having an electric panel mech?
     
  3. skegemog

    skegemog New Member

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    Thanks for your response. There seems to be enough power to run both mechanisms. The delay is the crux of the problem. I could do a mechanical link but I would like to use the the RF remote switch which means that I get basically two outputs: 30 vdc +- and 30 vdc-+. if I use limit switches to prevent interference I end up with one mechanism not able to reverse at the limit of its travel at one end and the other unable to reverse at the end of travel at the other end.
     
  4. dave

    Dave New Member

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  5. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Diodes can be used to route current so that limit switches can work at both ends of the travel.
    What current do the two mechanisms require?

    If you don't link the two mechs mechaniclly then presumably you'll need to do something like:-
    Use limit switches at each end for both panel and TV and:
    In response to 'TV on' command
    (1) open panel
    (2) use panel limit switch to start TV lift
    In response to 'TV off' command
    (3) lower TV
    (4) use TV limit switch to start panel close

    So delays would be inherent in the travel times and no electronic delay would seem necessary.
     
  6. alec_t

    alec_t Well-Known Member Most Helpful Member

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    You say you've got 30V on two of the pins, yet the motor is rated at 19.1V :confused:
    Do you have a schematic/datasheet for the control box?
     
  7. skegemog

    skegemog New Member

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    don't know the lift mechanism has no schematic and the drive motor for the panel I bought off of ebay with no documentation other than a requirement of 19.1 volts. That being said I have been powering both mechanisms by jumping wires off of the control box with no apparent loss of performance.
     
  8. skegemog

    skegemog New Member

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    this sounds like a solution I would like to try. How to start?
     
  9. skegemog

    skegemog New Member

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    the power brick that came with the lift and control box is rated 30 volts output at 2 amps
     
  10. alec_t

    alec_t Well-Known Member Most Helpful Member

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    I'm surprised you haven't let the magic smoke out of the 19V motor. Something must have limited the current (thin connecting wires perhaps?). It will have a short life if you use a 30V supply with it. You will need a ~19V supply.
    Do you know if the limit switches built into the TV-lift mech are change-over switches (SPDT), or simple open-at-limit (SPST) type? I'm guessing the latter if the connector is only 6-pin.
    Can you identify which pins of the connector go to the limit switches?
    Are the limit switch connections floating or are they tied to one of the +_30V rails?
     
  11. skegemog

    skegemog New Member

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    the thin wires must have been protecting the motor
     
  12. skegemog

    skegemog New Member

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    I can find one but does that then prevent me from using the RF switch from the TV lift to activate the panel lift?
     
  13. skegemog

    skegemog New Member

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    I don't think they are change over switches as the lift reaches it's limit and the lift stops but the current at the pins remains the same. The RF switch has two buttons (up and down) and you have to hit one the opposite one twice to reverse direction. you can hear the relays tripping when you hit the buttons but not at the end of travel.
     
  14. skegemog

    skegemog New Member

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    I'm sure I can figure this out but the unit is at my shop and I am already home, I can take a look tomorrow. Thanks for all your help!
     
    Last edited: Aug 13, 2012
  15. 4pyros

    4pyros Well-Known Member Most Helpful Member

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    Try and make a drawing with as much info as you can. Take pitchers if you can.
     
  16. alec_t

    alec_t Well-Known Member Most Helpful Member

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    Can you give more info on the make/model etc of the TV lift/controller/motor?
     
  17. KJ6EAD

    KJ6EAD Member

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    It may not be a problem to run a 19V motor at 30V for short periods especially with light loading if the 19V is a continuous rating. It also would not surprise me if the controller was capable of operating at a lower voltage like 24V which would be a good compromise for both motor and controller.
     
    Last edited: Aug 14, 2012
  18. alec_t

    alec_t Well-Known Member Most Helpful Member

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    TV lifts typically operate at ~ 25mm/sec, so will run for ~ 20 secs. I guess the panel motor could be operating for a similar time? The panel load may not be light. We don't know what the mechanism is.

    Is the TV lift a TS460 or similar (that has a 30V supply but the internal motor is 24V)?
     
  19. skegemog

    skegemog New Member

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    The lift is something sold as as a "Whisper Ride 700" sold in the States by a company called Wood Technology. From what I can tell it looks as if the product is actually made in Denmark....
     
  20. skegemog

    skegemog New Member

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  21. skegemog

    skegemog New Member

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    the motor that drives the panel could be changed, I just happened to have that motor on hand. I could probably find a 48 rpm gearhead motor at the appropriate voltage. I really want the simplicity of an integrated one controller system if I can get it
     

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