Low-voltage switch circuit.

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

  1. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    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

    Messages:
    2,559
    Location:
    North Carolina
    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

    Messages:
    798
    Location:
    Metro NYC
    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 Master of one

    Messages:
    4,450
    Location:
    Houston, TX
    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

    Messages:
    798
    Location:
    Metro NYC
    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 Master of one

    Messages:
    4,450
    Location:
    Houston, TX


    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

    Messages:
    798
    Location:
    Metro NYC
    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

    Messages:
    408
    Location:
    Santa Clara, CA
    It sounds like some kind of magnetic amplifier.
  9. ActionDave

    ActionDave Electrician

    Messages:
    361
    Location:
    Colorado
    So which is it?
  10. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,450
    Location:
    Houston, TX


    This has to be one of those 0 phase systems.


    Sounds like FM.
  11. Wet_Boots

    Wet_Boots Sprinkler Guy

    Messages:
    798
    Location:
    Metro NYC
    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:
    361
    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 Master of one

    Messages:
    4,450
    Location:
    Houston, TX
    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

    Messages:
    2,559
    Location:
    North Carolina
    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:
    798
    Location:
    Metro NYC
    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 Master of one

    Messages:
    4,450
    Location:
    Houston, TX

    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

    Messages:
    1,348
    Location:
    Cincinnati OH
    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 Master of one

    Messages:
    4,450
    Location:
    Houston, TX

    What a Great RFI Generator.
Similar Threads: Low-voltage switch
Forum Title Date
Electrical Forum discussion & Blog Connecting low-voltage conduit to electrical boxes Jun 21, 2008
Electrical Forum discussion & Blog Question regarding wireless light switch Oct 15, 2014
Electrical Forum discussion & Blog Converting Two Recessed Lights on a Single Switched Leg Jun 16, 2014
Electrical Forum discussion & Blog a single 3-way switch controlling a light fixture on a knob & tube circuit - why? Jun 12, 2014
Electrical Forum discussion & Blog 3-way switches with dimmers for lighting? May 2, 2014

Share This Page