SmartThings Community

Momentary Pull Cord and Micro Switch

Is there a setup that will use a microswitch (Aeon or Fibaro ETC) that once pulled will know what status it should be in.

I have a HUE bathroom bulb and want the pull cord to work for guests. If they pull it the light will come on or off as you would expect like its a real switch but in reality its all virtual. The issue is when you pull once the micro switch will think its on.
If the light is turned off using Alexa or some routine then next time I pull it will try to turn it off. but actually it needs to turn on.

I know WebCore could possibly change the state of the switch. but looking at ideas here.

My other option is ditch the pull cord and use a Hue dimmer.

A Aeon microswitch will work exactly the way you describe. The default behavior is the load (light) will toggle (in reality and in SmartThings) whenever the switch that’s connected to it changes state. So if the lamp is on, either opening or closing the switch will turn the lamp off.

A physical switch connected to a microswitch is just a low-voltage contact-closure input. It does not cary high voltage to the load.

The only challenge would be wiring the pull-switch to the microswitch separately from the lightbulb. The pull-switches I’ve seen are directly connected to the lamp socket. But these are pretty simple devices… I bet if you took apart a porcelain socket the project would be clear enough.

So I can get above both the light and pull switch. I will have a neutral feed easily enough. Obviously I don’t want it to directly control the power of the light as I need that to be live always. So how does the switch know which to do?

The microswitch just changes the state of the light whenever it receives a change in state from the switch. It doesn’t matter which position (on or off) the switch is in, or if the light is on or off. All that matters is that the switch changes. The microswitch will do the rest.

Nearly all UK pull cord switches are toggle switches. Once for on and once more for off. The Modules (Aeon, Fibaro) can cope with this, although it does make it difficult to use the dimmer functions. If all you need is on/off then that would be OK. If you want to use the dimmer function then a momentary is needed.

I have found it quite difficult to source UK monetary pull cord soothes. the only way I found is to use the ones designed for emergency notification like the red cords you might see is a disabled to elderly persons bathroom. However a red cord is not nice and not easy to change. I have found an MK pull to make/break version that has a red cord, but only the bottom part. The top part is white so you could change the bottom part and Bobs’ your uncle!

@siwilson
Yes I found the same MK pullcord switches. It should be easy to change the cord on these.

See - https://www.mkelectric.com/en-gb/Products/WD/ceilingaccessories/Ceilingswitch/6ampsurface/Pages/3190RCWHI.aspx
and - https://www.electricaldirect.co.uk/product/mk-6a-momentary-pull-cord-switch-with-red-cord-white-932149

Typically you would use these with a Fibaro, Aeon, or even Insteon micro switch to actually turn on or off power to the light. However in theory it could be used instead to send a signal to say Smartthings which then sent the signal to say the Philips Hue hub which then turned the bulb on/off rather than the power.

My own plan is to stick with directly controlling the power and not using smart bulbs.

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