Stumped on my "Batman" bookshelf

Discussion in 'The Projects Forum' started by chekhov, Mar 23, 2014.

  1. chekhov

    Thread Starter New Member

    Mar 23, 2014
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    Hi everyone.

    I've read through some similar posts related to my confusion, however I've become slightly more confused :D

    I didn't want to hijack anyone's thread, so I thought the polite thing to do would be to start a new thread.

    SETUP:

    Bookshelf/hidden door leading to balcony, opening by a 12v linear actuator.

    I currently use a DPDT switch, thrown into a shakespeare bust. It triggers a 12v red LED upon switching the toggle to on, as well as sending power to the actuator to operate the door. Flip the switch in reverse...reverses the polarity


    Here's where I run into problems:

    I cannot for the life of me figure out what I need in order to throw another switch on the opposite side.

    I'd still prefer to go with the toggle switches (on-off-on). They are no momentary in either of the 3 positions.

    I'm assuming I need some form of relay, but when it goes down that road, I'm completely lost.

    From my understanding, I'm going to need 2 or 3 relays to do what I want, but again, not sure of anything at this point.

    I'd really appreciate any help in solving this because I'm wanting to keep the mosquitoes on the outside :D

    Also, it would be of BIG BIG BIG help if alongside your reply, you provided an amazon link of the item so I can buy it/them immediately.

    Again, I really appreciate any help any of you can provide!

    All the best
     
    Last edited: Mar 23, 2014
  2. Little Ghostman

    Member

    Jan 1, 2014
    294
    97
    Not sure if I am understanding this correctly, but have a look at how light switches are wired in house for stairs etc, so you can turn them on or off from either from the top of the stairs or the bottom.
    If I get what you mean then that should be pretty easy, but I might have it wrong in my head
     
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  3. wayneh

    Expert

    Sep 9, 2010
    12,126
    3,048
    You may want to read this or this. Nice explanations.
     
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  4. chekhov

    Thread Starter New Member

    Mar 23, 2014
    6
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    Hey, thanks for the reply.

    I'm not sure if the concept is the same, but I think we're looking a couple of different things here.

    Correct me if I'm wrong, but I don't think a three-way switch (stair lights) reverse the polarity. I think they just toggle the power on & off. I need to not only toggle the power on & off, but to also reverse the polarity with the use of two switches :-/ Not 100% sure, even after reading more into 3-way switches, if it can do that.

    Still looking into it :)
     
    Last edited: Mar 23, 2014
  5. chekhov

    Thread Starter New Member

    Mar 23, 2014
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    0
    I hate the internet :D I keep finding posts saying I can, but I can't. Or I can't, but I can with the 3-way setup.

    Then anytime I type in reversing polarity on a 3-way switch, I get DPDT toggle switches with no explanation. :-|

    *It also may be worth noting that I've configured it as a 3-way, and it presents a different problem. The motor stops working when stroke is fully extended. Great! But, when you flip the other switch, as you would on a light, it wants to retract, but the other side (still flipped up) starts drawing power again once it goes about 1/2" retracted & then it's a battle between the two, in a very still, but loud process.
     
    Last edited: Mar 23, 2014
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    Do you have any extreme end limit SW? or Does the L.A. have them built in?
    If so there have been diag posted here with a diode across each limit and a DPDT switch for reversing.
    Max.
     
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  7. chekhov

    Thread Starter New Member

    Mar 23, 2014
    6
    0

    Hey, thanks for the reply.

    Although, I do appreciate it, you have lost me :)

    If by extreme end limit, you mean auto-shutoff when it's reached the end of the stroke, yes it does that. But, once retracted by the other switch even slightly, it kicks back in and wants to extend to the full length while the other switch is telling it to so the opposite.

    Clearly, I may have misunderstood what you were saying, so if I did, so enlighten me.

    All the best!
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
  9. chekhov

    Thread Starter New Member

    Mar 23, 2014
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  10. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    You would need to gain access to the two limits and wire a diode across each as shown, if they do not already have, or modify the internal wiring to suit.
    It may take a little 'reverse engineering'.
    This way you still end up with two wires to the L.A.
    Max.
     
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  11. chekhov

    Thread Starter New Member

    Mar 23, 2014
    6
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    Any chance any form of relay or "ready-made" device can be used?

    I'm not familiar, much less comfortable taking it apart without a little more knowledge on it than I currently possess.
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    It would be good to know how the internal L.S. are wired now, do you have any info on the actuator at all?
    Or model No, Pic etc?
    Max.
     
  13. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    Here is the same diagram without the diodes.
    The diode one seems simpler to me!

    If limits are internal to actuator, they will have the diodes in place. Just wire switches as shown.
    What you need are "4" way switches. They reverse polarity. Any number of switches will work.
    "4 ways" are internally wired as I have shown.

    Just ignore switch jumpers and wire:
    Power in to one switch. (two wires)
    Two wires from first to second switch.
    Two wires from second switch to motor.


    The "M" shows the two wires from motor.

    Second is a diagram with a second switch added.
     
    Last edited: Mar 23, 2014
  14. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    And simplified 4 way switches.
     
  15. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    In the event that the travel limits of the actuator are only stand alone devices, this may work for you.
     
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