ᐅ Looking for: electronically controlled double-pole / two-way switch

karl.jonas schrieb:

2. Could this make sense (I know many alternatives are discussed here)?
Or would it be obviously more reasonable (for professionals) to plan the entire system right away using push buttons and impulse relays?

Note: Not a professional! If the goal is just to build a robust system, it can certainly be done with push buttons and relays; this has also been proven reliable in the corridors of countless apartment buildings for years. However, I would point out that relays may produce audible “clicking” noises. I would pay attention to that. Otherwise, I think Shelly devices might be an option over WiFi (I’m not really familiar with them, and WLAN solutions are a matter of preference). Searching for “Shelly” and “two-way switching” seems to yield quite a bit of information.

Benutzer200 schrieb:

Why not just install a few Shellys then?

For one or two reasons (depending on the Shelly model). The main reason is that Shellys are installed inline with the lighting circuit and control the lamp. The switches then operate the Shelly. This means if the Shelly fails, the light stops working.

Most Shellys use Wi-Fi. This is great for retrofitting, but anyone familiar with wireless prefers wired solutions—at least if it can be done without excessive effort.

Combining "smart" switches with two-way switches doesn’t seem like a good idea to me.

With the "smart" part, it’s no longer clear what will happen when it switches. Depending on the position of other switches, the opposite effect may occur.

Additionally, a multi-way switch setup with four switches is expensive and complex.

karl.jonas schrieb:

Most Shelly devices work with Wi-Fi. That’s great for retrofitting, but if you’re familiar with wired connections, you’ll prefer cables—at least if that can be done with reasonable effort.

In that case, you should use KNX directly and avoid a (complicated) DIY solution.

RotorMotor schrieb:

Combining "smart" with two-way switches doesn’t seem like a good idea to me.
For the "smart" part, it’s no longer clear what happens when it switches. Depending on the position of the other switches, the opposite action might occur.
Moreover, a two-way switch setup with 4 switches is expensive and complicated.

That’s true. With such a setup, the "smart" part couldn’t simply turn the light on or off; it could only toggle it. Detecting whether it’s dark and therefore the light should be toggled (for example, with motion detection) seems straightforward. The other way around might be more difficult, because when it’s bright, I don’t yet know if the light is on or off. So, I would need a “lamp is switched on” detection for that.

In our bathroom, the main lighting is controlled by a standard wall switch located outside in the hallway, as originally planned.

However, it turned out to be too bright for us. So, I installed a Hue E27 bulb in the ceiling fixture and replaced the hallway switch with a Hue smart switch. This allows me to control both the color temperature and the brightness. The wall switch is always set to "ON." Next to the mirror cabinet, I installed an identical Hue switch that also controls the same light fixture, so you can fine-tune the lighting from there. You could also integrate a PIR motion sensor switch if desired.

If there is a two-way switch instead of a simple one, you set it once to "on" and then use only the Hue switch for control. If the physical switch fails, you toggle it off and on again, and it works like a regular light with a two-way switch.

Conventional switches can also be converted to power outlets if needed (by running the wiring through and installing a Schuko socket insert in the box).