Mutually exclusive "on" for 2x devices (in this case dimmers)

[MrNoTip 2]

Hello,

 

 

Background:

 

I have 4x Warm/Cool downlights. The manufacturer sells these as a three wire downlight with a smart wifi driver to control bothg warm and cool.

 

I have figured out a way  to treat these as two separate lighting circuits - they share a common positive, but the negative(s) each go to a separate dimmer. Net result: I have 'warm' and 'cool' lighting just a click away with two buttons on the wall.

 

The problems is that these lights have no power limitation - a CV driver will destroy them....I have to feed each light 550ma only. 

 

Problem is, I can accidentally turn on cool without turnin off warm....net result, each light has 1100ma going thru it. What's worse, once I rush to turn one or both off, one or two lights will randomly flash and I have to dim/on/off a lot to get them to settle down.

 

 

Goal:

If a request to turn on dimmer 1 is received, turn off dimmer 2 first (if it is on)

If a request to turn on dimmer 2 is received, turn off dimmer 1 first (if it is on)

 

So far:

I've tried a basic block scene, but these work more like:

As dimmer one turns on, turn off dimmer 2.

That is not a blocking logic, and the two circuits are on at the same time.

 

So...

Is there a way to prevent one circuit even turning on until the other turns off, while still using standard dimmer 2 physical switches and minimal delay?

 

[Tim__ 126]

Assuming you aren't using an HC lite, You can easily convert the block code to LUA and then edit it from there, to make the logic that you describe. Just add commands that switch off both dimmers before turning on the selected one on. (This should be possible with a home centre 2 block scene i would have thought??).

It is still possible though, to have both dimmers on at the same time (for example, by clicking in the GUI). 

 

If you want a truly fail-safe method, you need slave relays connected to another fibaro device. The first relay is SPDT, and selects which colour. The second relay turns the whole light fitting on and off. This will require more hardware (fibaro dimmer + double switch + relays) and coding though! Up to you depending on the risk of having both dimmers on momentarily.