Low-voltage switch circuit.

Discussion in 'Electrical Forum discussion & Blog' started by Wet_Boots, Oct 3, 2013.

  1. Wet_Boots

    Wet_Boots Sprinkler Guy

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    I've seen one or two homes that had wall switches without any line voltage in them. I'm not sure what history would lead to someone having a rack of relays in the basement utility room sending power to ceiling lamps.

    One set of switches I recall involved something more practical, and that's why I'm posting this. These switches were controlling lights in and around a swimming pool, but with all the power coming from the pump room in the pool cabana. I remember these switches weren't controlling relays, but were closing a secondary circuit in some sort of transformer arrangement that I can't recall. I'm pretty sure the closed switch in the secondary circuit made for an increased magnetic field that was used to close contacts, so the function was like a relay, only there was no specific coil with a voltage rating needed to operate it.

    Any of this ring a bell? I rather liked the simplicity of the concept. I saw a data sheet for these low-voltage (or nearly "no-voltage") switching devices, but I just can't remember enough to locate them again.
  2. jwelectric

    jwelectric Electrical Contractor/Instructor

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    Low voltage switching of lights was a big thing years ago. What I have dealt with had a master control located in the master bedroom that controlled all lights.

    What you seem to be describing at the pool is X10 switches.
    http://x10pro-usa.com/
  3. Wet_Boots

    Wet_Boots Sprinkler Guy

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    Definitely not X10. Much more low-tech. Strictly transformer wiring and magnetism. The control circuit wasn't labeled as having any particular voltage or current. It was a UL-listed device, and not a home-brew circuit.

    I should add that this particular device could have predated the transistor - it was that low-tech
    Last edited: Oct 3, 2013
  4. DonL

    DonL Jack of all trades

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    Must be FM


    Was it Magnetism or Hypnotism ?


    Hypnotism.jpg


    http://www.astrologynspiritualism.com/articles_hypnosis.html



    The only system that I have seen like that used SCR's and Flux capacitors.
    Last edited: Oct 3, 2013
  5. Wet_Boots

    Wet_Boots Sprinkler Guy

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    I think the circuit diagram would look a bit like two transformers in a series connection, with the low-voltage switch interrupting the interconnection between transformers. I'm sure it's something more subtle, though. There might be a parallel winding involved.
  6. DonL

    DonL Jack of all trades

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    It may have been like these,

    http://www.douglaslightingcontrol.com/specifications

    Would be great for a Smart Home.


    Have Fun.
  7. Wet_Boots

    Wet_Boots Sprinkler Guy

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    798
    Location:
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    It must be something that was always obscure. I don't even remember how I located a diagram of its inner workings, in pre-internet days. I don't think it used anything but wires and magnetism to accomplish the task, and it did so without step-down transformers and relays.
  8. bluebinky

    bluebinky Member

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    Santa Clara, CA
    It sounds like some kind of magnetic amplifier.
  9. ActionDave

    ActionDave Electrician

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    So which is it?
  10. DonL

    DonL Jack of all trades

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    This has to be one of those 0 phase systems.


    Sounds like FM.
  11. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
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    My memories just can't quite connect the dots. Since there was supposedly very little power/voltage in the control wires, I think that probably rules out a circuit where you can see a turns ratio on a magnetic core. And yet, closing the circuit represented by the control wires would alter a magnetic field enough to open and close power contacts.

    You see the circuit diagram, and you get it, is about all I can add. And that even goes for my grudgingly obtained schooling in magnetics, where a weber is a charcoal grill, and a henry is the home run king.
  12. ActionDave

    ActionDave Electrician

    Messages:
    345
    Location:
    Colorado
    Sounds like an old R-7 relay system. 24V to switch boxes and remote latching relays to control the lights. Great system. Rugged, reliable, and flexible.
  13. DonL

    DonL Jack of all trades

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    Some of the newer systems are pretty neat.

    If you run DC you can go off grid without the need of inverters.

    With all of the Smart Meters used now a days, Remote controlling over the internet is getting popular.


    Have Fun.
  14. jwelectric

    jwelectric Electrical Contractor/Instructor

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    Here we are in agreement and one of the best on the market. I own two of them, one charcoal the other gas

    Now I must give a little rebuttal on this as Henry is the best darn rifle ever made
  15. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
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    Location:
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    A google search is not much use. Too much product out there accomplishing the same task with modern electronics. I might someday find an invoice that gives me the location where these switching units are probably still in place, and I might request a peek at them.
  16. DonL

    DonL Jack of all trades

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    I was very disappointed in the new Weber grills.

    The last one that I bought was made in China and you could tell it, compared to the old stuff.

    It cost over $100 and the other knockoffs of the same design were $40, but I bit the bullet and got the Weber Kettle.


    They were probably both made in the same China factory.
  17. cwhyu2

    cwhyu2 Consultant

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    Two words, Touch plate. Look it up I found it and I have worked them and was a PITA
    Last edited: Oct 12, 2013
  18. DonL

    DonL Jack of all trades

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    What a Great RFI Generator.
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