Connect with us

need help with small home lighting project

Discussion in 'Electronic Design' started by noel, Nov 9, 2003.

Scroll to continue with content
  1. noel

    noel Guest


    I need to build a remotely computer controlled 4way light switch. I
    want to do some home automation, and I can't use normal x10 3way
    switches. So, I need to build something. Most of the lights I want to
    conrtol are on 3way circuits. And the cost (in number of switches) and
    the color of the paddles excludes x10 switches as an option. All the
    switches paddles are black, and some are combination (3way/spst)

    I want to take a DPDT relay and use it as a 4way light switch. Using a
    DPDT relay takes care of the switching of the traveller wires on the
    3way/4way circuit. But now I'm left with a couple of problems.

    Upon looking on the net for relays, I've found two types. One is a
    latching relay that just requires momentary current to switch the
    relay, but these are low voltage DC for the coil, and use pos/neg to
    switch. The others are non-latching and require a steady AC current to
    maintain an 'on' state. I really don't want to use this type of relay.
    Is there any other type of relay? Something that uses momentary ac to

    I would like to use x10 to control the switch/relay. It would be nice
    to have a switch unit that didn't need control wires running to it.
    Not that I'm against running more wires, like low voltage to control a
    latching relay. It's just that on the computer side, there is more x10
    software and interface hardware to choose from (that I know of).

    Another problem is sensing if the light is on. I've seen little loop
    sensors that send an induced voltage to a universal x10 module. But,
    this seems a little problematic. if you try to sense on the two
    traveler wires, you have to use two sensors and travler wires seem to
    have some voltage induced in one by the other.

    With what little i know, I guess my best choice is to use a latching
    relay that uses low voltage dc to control the relay and run wires to
    some kind of interface, and figure out someway of load sensing.

    If anyone could give me a few suggestions on how to accomplish this,
    or offer some other ideas, it would be of great help.

  2. Jim Backus

    Jim Backus Guest

    At the risk of making a complete fool of myself, because I'm not
    familiar with either US wiring practice or X10, but if there is an X10
    3 way switch, surely this is suitable for an n-way switch?

    A 2 way switch operates with a single pole double throw switch at each
    switch position. The moving contact is linked through a 3rd wire. The
    first wire connects fixed contact 1 of both switches together, and the
    second wire connects fixed contact 2 of both switches together.

    The 3 way switch is a 2 pole 2 throw switch which is wired as a
    changeover switch and is wired in series with wires 1 & 2. Because the
    3 way switch is a 2 pole changeover switch and number of these can be
    fitted in the circuit.

    My apologies if this is completely wrong!
  3. Jim Thompson

    Jim Thompson Guest

    Only the names are wrong

    2-way is single-pole-single-throw, ordinary switch

    3-way is single-pole-double-throw, on each end of a multi-switch setup

    4-way is double-pole-double-throw, located *mid-stream* on a
    multi-switch setup

    The naming "convention" seems to be based on number of terminals and
    not on something sensible/meaningful ;-)

    ...Jim Thompson
  4. N. Thornton

    N. Thornton Guest

    Hi Noel.

    This is as clear as mud.

    what are?

    traveller wires?
    the what?
    sounds an elementary issue.

    for what purpose?
    Yes, clarity would be good.

    Regards, NT
  5. noel

    noel Guest

    I believe that the UK and the US refer to these switches differently.
    I've seen this noted on a couple of websites.
  6. Sure it makes perfect sense, if you're an electrician! They count the
    number of positions, before you start the cycle over.
  7. X10 3-way switches can be used to form N-way switches. Basically the
    X10 3-way has a master and a slave. The slave is momentary switch that
    signals the master to toggle using one of the "travelers". The other
    traveler is used to switch the current. To create an n-way switch one
    simply wires the slaves such that each signals the master.
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day