Latching Relay

Discussion in 'General Electronics Chat' started by DYLH, Aug 14, 2013.

  1. DYLH

    Thread Starter New Member

    Aug 13, 2013
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    Hello- I have a curiosity about how the lights in our home work. I'm familiar with 3- and 4- way switches, but I know that isn't what we have in this case.

    We are in europe living temporarily. There are latching relays (line voltage) in the power panel, and momentary contact switches. E.g., for the lights in the basement there are 4 switches w/ temporary contact.

    In some cases, there are 2- switches that can be used to turn on or off the light in a particular room/corridor.. in other cases, there are 3.

    I'm curious how this is all wired for a given 'light'... I've searched google and through this forum, and haven't stumbled across what I would expect... could someone 'dumb it down' for me, and provide a simple diagram?

    Thanks much.
     
  2. MaxHeadRoom

    Expert

    Jul 18, 2013
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    A little more is needed, are you saying all these switches you refer to are momentary type, rather than the usual maintained?
    Max.
     
  3. DYLH

    Thread Starter New Member

    Aug 13, 2013
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    Yes, all the switches are temporaray contact.

    Here's what I *think* is going on... I'm also curious how the 'guts' of the relay look.

    [​IMG]
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    But is a respective momentary switch also used to turn the light off, IOW, Toggle action?
    Not sure of the thinking behind using this method?
    Unless they automatically turn off after a certain time delay?
    Max.
     
  5. DYLH

    Thread Starter New Member

    Aug 13, 2013
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    Yes.. all switches can be used to turn the light(s) on or off (toggle).
     
  6. odinhg

    Active Member

    Jul 22, 2009
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    DYLH likes this.
  7. MaxHeadRoom

    Expert

    Jul 18, 2013
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    If no time delay is involved, the only reason I can see is to save one conductor over 2W,3W and intermediate switching?
    Max.
     
  8. DYLH

    Thread Starter New Member

    Aug 13, 2013
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    Perhaps... also, makes it a lot easier to 'draw'... don't have to keep track of all those tick marks on the CAD plans ;). The method seems pretty pervasive in europe. Since they pull cables, instead of wires, perhaps makes it less inexpensive to install labor wise, as they don't have to have extra stock of different types of cables.

    Dunno.. to each their own, I guess.
     
  9. BillB3857

    Senior Member

    Feb 28, 2009
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    I took an old X-10 appliance module apart and it uses a solenoid pulsing a ratchet wheel. The wheel has a cam lobe which operates the movable contact of a relay. Each pulse of the solenoid advances the cam and alternates OPEN-CLOSE-OPEN-CLOSE on the switch. Maybe you have something similar.
     
  10. gerty

    AAC Fanatic!

    Aug 30, 2007
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    Sounds like you have what we used to refer to as "low voltage control lighting". It was used in the US in the 60's and it's claim to fame was the reduced initial cost of wiring. It used low voltage, latching relays, mounted at either the fixture box or the main panel.The relays were a dual coil latching type, typically 24 vac.
    I still have one on one of my old wiring trainers.
     
  11. DYLH

    Thread Starter New Member

    Aug 13, 2013
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    Thanks, odinhg! Yep, looks like the 'TL' is the same type of device... the schematic there is right in line with what I was suspecting.
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    It appears the main object is for low current switching device to control 32+amp lighting circuits, where many illumination points are fed from single low current switches.
    The 1 pole and 2 pole devices can be stacked together to form multi-pole distribution.
    Max.
     
    Last edited: Aug 14, 2013
  13. doug08

    Member

    Jan 30, 2011
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  14. sheldons

    Active Member

    Oct 26, 2011
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    heres how it is wired over here in the uk-240v ac supply -2 way switching using twin and earth and 3 core and earth-very easy with an additional switch to provide 3 way switching....no relays required.....
     
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