3-way switching

[KeepItSimpleStupid]

That's news to me. Maybe there's a US/UK divide on terminology . Like you though I don't see the logic in it.

Switch, LIGHT (2-way or two things)
0...........0
1...........1

Switch A, Switch B, Light (3-way three things)
0...............0.............0
0...............1.............1
1...............1.............0
1...............0.............1

Logical?

 

[Dr_Doggy]

Why are you ignoring the simple XOR solution?

cos i dont think its what he wants, it sounds like he has his switches under control, doing whatever they do, i dont think he wants to do switching, just read the value of the switches, it sounds to me like he has multiple devices, multi switches, and multi sources,

edit\:my bad... just noticed what he thought a 3way was... logic above is def xor

 

[ljcox]

Switch, LIGHT (2-way or two things)
0...........0
1...........1

Switch A, Switch B, Light (3-way three things)
0...............0.............0
0...............1.............1
1...............1.............0
1...............0.............1

Logical?

No, I don't find it logical. One switch has two states, two switches have four states as shown in your table.

So you could, if you wanted to, you could call it four way.

In Australia, as in the UK we call it two way switching.

That is why Pommie in post #5 had three switches in his circuit.

Incidentally, his arrangement (as any the electrician would tell you), can be extended to any number of switches.

The switches at each end are SPDT and the intermediate ones are DPDT.

 

[KeepItSimpleStupid]

Hey,thanks. Seems like there is some terminology differences: https://en.wikipedia.org/wiki/Multiway_switching

 

[MikeMl]

I think the OP gave up...

 

[ljcox]

Hey,thanks. Seems like there is some terminology differences: https://en.wikipedia.org/wiki/Multiway_switching

Thanks, I now see why you call it 3 way. The 3 way refers to the switch, a SPDT is called a 3 way & a DPDT is called a 4 way.

Whereas our terminology is based on the number of switches.

 

[greghl]

sorry for not getting around. been busy. the XOR gating will work for what i want perhaps witha microcontroller. Sorry for the confusion with the 3-way switching. 3 way switching when refferring to 120v wiring in a house or office consits of two switches controlling one light/ switch leg. A four way switching scenario refers to the to 3 or more switches controlling a light/switch leg. i am an electrian by trade. the three way refers to the fact there are three terminals on the switchs, two travellers and once common. four way has four terminals 2 sets of two for travellers.

 

[greghl]

Regarding me being unable to add wires for the travelers that is corect. i want to use existing wiring in the walls. I only have access to one spare wire. i was hopiing i could switch it to ground to get the state of the switch with perhaps a not gate.

 

[ljcox]

The confusion about three way switching vs. two way switching was not your fault. It is due to the different terminology used in the US vs. that used in the UK and Australia.

I have not heard the term "travellers" before so I assume that it is a US term. As I understand it, it refers to the wires between the switches.

You said you have one spare wire. Have you considered the possibility of using a relay rather than electronics? If you use electronics, you will need a DC supply voltage & a relay anyway in order to interface to the 120 Volt wiring.

The relay could be operated by an AC supply by using either a high voltage relay or low voltage relay (say 12 Volt or 24 Volt), a transformer & a rectifier bridge.

I'm happy to post a diagram for you if you don't fully understand what I mean.

 

[greghl]

The only concern would be the size of the relay. I know i will already need one set of contacts. maybe you could post a diagram.

 

[ljcox]

The only concern would be the size of the relay. I know i will already need one set of contacts. maybe you could post a diagram.

It would help me if you posted a diagram of what you're wanting to do.

The verbal description in your earlier posts is hard to follow.

A picture is worth a 100 words.

 

[greghl]

View attachment 67071

here is a diagram of the situation. Everything you see is highvoltage 120 V wiring. This is a remote module controling a fan/light combo. The module needs a hot at all times and a neutral. pressing buttons on the remote will change speed of the fan and the light along with timer functions for both fan and light. this module is the only way to control the fan, with diferents speeds and direction, there are no pull chains on the fan.

The annoyance is the fact that the wall switch doesnt do anything. and to turn on the light when you enter or leave the room you have to find the remote. very annoying. i suppose the easiest thing to do would be to disconnect the light socket from the control module , cap it off, and connect it to the red wire which would be conected to a switch. I would have then 120v always on the control module to control the fan and fan speeds( it could still switch the light SL wire but it would be capped off) and then have the lights controled from a SP switch. This would be a compromise. I would be a treat to have the light controlled from the remote as well as the wall switch.

NOw the biggest problem for me is to keep everything hidden, i have a decent amount of room in the switchbox, some in the octagon and some in the canopy of the light.

The module does work off of low voltage, there is a transformer in the module.I was kinda thinking having the light sl coming off the module go to the coil of an AC relay, have the contacts interupt a lv source( tapped off the module supply) going to a pin on a XOR gate. then have lv source,( supplyed from battteries maybe?) in switch box going up red wire to other leg of XOR gate. The output of XOR gate thhrows relay with LV coil to switch on Light.

potential problems. Size of relays, Is the psu in module AC or DC( need to rectify anything). with the switch on the wall; perhaps send down lv source to $ and ground it. Microcontroller could read this as change in state.

Like i said i am more familiar with electronics than most commoners but still a newbie. I am thinging i may just have to bypass the module control of the light and use a regular 120V switch. I just like trying to figure out if i can make stuff do what i want, how i want it. If anyone has any insight im mopen to suggestions. I understand its kind of a silly project. i jsut find it fun to brainstorm this stuff out.

ps. heres a link to the fan/light controller. similar to the one in my light http://www.insteon.net/2475F-fanlinc-ceiling-fan-light-controller.html

 

[ljcox]

Thanks for the diagram, it makes it much clearer.

What does SL and lv mean?

I'll study it more later. I have other things to do at the moment.

Now I've had a more time to stuy your diagram, I can see what SL & lv mean.

You said that the switch (presumably on the Switch Box) does not do anything.

I assume that this box is downstairs. Or is it upstairs with in the same room as the CM, Fan & light?

So my assumption of what you want to do is

1. make the switch on the Switch Box control the light, but not affect the 120 V going to the Control Module.

2. be able to still turn the ligt on/off with the remote.

 

[ljcox]

I have thought further.

I have attached a SDL (System Description Language) diagram to describe what I think you want.

If not, please modify it to show what you want.

I hope it is self explanatory. If not, let me know what is not clear.

 

[greghl]

switch does not do anything at the moment. i have it mounted but not connected to anything because i didn't have a blank coverplate

the box is in the same room as the fan. the control module is in the canopy of the fan/light combo

your assumptions are correct. Ideally I want to control the light from the wall switch and from the remote control. In doing this I can not distrupt the 120v going to the control module. If we do, then the remote control will be UNable to control the light and the fan.

just give me a minute to learn how to read your SDL. Upon first glance I see you included the fan states. The fan works independently from the light. the fan should not be included in anything we do.

 

[greghl]

Your SDL looks like what i want to do.

 

[ljcox]

just give me a minute to learn how to read your SDL. Upon first glance I see you included the fan states. The fan works independently from the light. the fan should not be included in anything we do.

I understand that, but the Fan must be an input to the SDL. If the switch was the only input to the SDL then it would be just a simple on/off switch with no need for any relays or electronics.

The system that will be designed from the SDL will not have any effect on the Fan. In other words, the Fan will be exclusively controlled by the Remote.

Re your post #36. Good, I'll work on it as time permits & post a suggestion for you in a day or 2.

In the meantime, I suggest you investigate the availability of a suitable relay. Also, I may need to know the voltage of the DC supply in the fan unit & whether you can attach wires to the unit so we can use the DC for the proposed light controller.

 

[ljcox]

Here is the detailed SDL. The previous one was a basic outline.

Please check it to ensure that it is what you want and to find any errors I may have made.

I will modify your wiring diagram tomorrow in order to show you how the Light Controller will fit in.

The electronics would be easier if you use a PIC.

Are you able to write PIC programmes?

Do you have a PIC programmer or know someone who does?

 

[ljcox]

Attached is an outline of what I propose.

I will await your response to this and my previous posts before proceeding further.

 

[greghl]

I do have access to a PIC programmer. I have done a little bit before. Per your wiring diagram It looks like the remote will not be able to turn the light on. The only interface between the OEM stuff and the addition is the VCC.