Multi-way light switching - are there 'electronic' ways to do it?

[tinnews]

I know the normal way to provide multi-way light switches is using two SPCO switches and intermediate switches for however many more ways one needs.

I want to do the same but using only SP on-off switches because the shape and size of switch I want to use is only available as single pole on-off.

Obviously one can do this using a relay controlled by each switch (two SPCO and the rest DPCOs wired to provide the intermediate switch action) but I was wondering if there are ICs manufactured for doing this. If they can control lights (12 volt, an amp or two) directly then so much the better but I'd be happy enough to add power switching to a low level device if necessary.

[Andrew May]

From a purely electronic point of view if you had a low voltage supply use a pull-up resistor to the 5v and use the switch to ground other end. Wire all of these to an exclusive-or gate and use the output to switch a relay to control whatever load you need.

[NT]

You could just use a digital 4000 or 74LS series IC so that any operation of any switch changes the output or on/off state. Add a relay to drive the lights, and a transistor to drive the relay.

NT

[Huge]

You could use a Raspberry Pi ...

:o)

[Mike Barnes]

[e-mail]:

You could take a look at Easy Switch (e.g. from TLC). No mains required at the switch, it operates by battery-powered radio that fits behind your switch in a deep back box. In "double" mode, changing the position of any registered switch will toggle the receiver output, which is an uncommitted SPDT relay. Although it's called "double" mode I imagine it will work with any number of transmitters.

[Andrew Gabriel]

Can you get momentary action types, i.e. with a sprung return? If so, you can use am impulse relay, which is how it's normally done in some other countries.

My light switching is mostly done electronicly, so I need lots of momentary action switches. I often end up inserting the momentary action springs from other switches, when I find that I need it in a form that doesn't exist.

[Harry Bloomfield]

Much easier with several push buttons instead of a switch - wire in as many as you want, one pull-up and just one wire around all of the buttons. First press turns it on, second press (of any button) turns it off, even use a timer IC to turn it off after a period of time.

[jgharston]

Points, not ways. Unless you really are asking about controlling a traffic light.

This is a multi-way switch:

o------ o------

---o----->o------ o------ o------

What you're desribing is multi-/point/ switching, having several switches as several points (or places). This is done using

*two*-way switches:

o-------------------o

---o----> X

[tinnews]

Possibly, though I'm now tending towards using relays. DPCO 3 amp relays which would be perfectly adequate for what I want to do can be bought for quite a lot less than £1, stick two or three on a piece of veroboard and hide it away somewhere and the job's done really. It also allows me to use ridiculously thin wire to the switches which might be quite an advantage.

[tinnews]

Yes, I know that's strictly correct, but "two way switch" in a domestic setting means what you call multi-point.

[Andrew Gabriel]

In the US, a "two way switch" is a "three way switch", because it's got 3 terminals.

[Frank Erskine]

Presumably a DPDT switch is known in the US as a six way switch... :-)

They really haven't much of a clue.

[John Rumm]

A pile of bistables...

Use one on each switch to convert it from edge to pulse operation. Then "or" all of those together and feed a T type bistable to toggle its output on each pulse.

You would need some debouncing on each switch though, or you will get loads of edges per switch operation!