Aqara Light Switch - "no neutral" vs. "neutral" version

There are two different models of the Aqara light switch, a “no neutral” and a “neutral” version.

You can find it here

The know how the smart lightswitches that need a neutral wire work (like e.g. sonoff wall switch).
The usually need three wires. Live wire (L), Wire to the bulb (L1) and a neutral wire (N) to power the device itself.

Now I found this no-neutral version from aqara and I’m wondering how this works. They even mention that in old building there usually is not neutral wire in the wall switches.
So as I understand this works with only two wires like a normal “dumb” wall switch works, but how is this device powered?

Only thing I can imagine is a battery or it dimms the light down to zero, possible leading to glowing leds.

Would be nice to understand how this works.

See:

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I have 12 of these switches. In the UK most light switches only have 2 wires (the third is earth)

see
https://www.vesternet.com/resources/application-notes/apnt-23/

The switches simply turn the power on and off. There is no dimming . They need a load on the circuit to work correctly see

https://blog.tlpa.nl/2017/11/02/xiaomi-aqara-wall-switch/ ( this shows the neutral version)

check the specs here

https://www.aqara.com/en/ctrl-neutral.html

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Thanks.

The thing is I’d like to understand how they work.

With an old manual switch and a two wire installation, it is me that pushed to switch to close the circle.

I get the three wire (neutral version aqara switches). Here you need the neutral to power the aqara switch, so it can turn on the relay.

I’m simple wondering how this works with the two wire version. Because to switch the relay and be able to receive commands it needs power. But if the Relay is on (to power the device) the light after that relay will also lighten up.

That is why I think it dimms down the to the power the aqara device needs. But I might be wrong and would be glad if something brightens that up for me.

so no one knows how this works?

I’m wondering too.
I can only assume it works in a similar way to the Fibaro Dimmer 2/3 (when set without the N wire) and it’s really dimming the light to almost 0.

don’t know that one

https://manuals.fibaro.com/dimmer-2/#post-1164

Interesting but I couldn’t find that they say how it actually works.

Also I’m struggling a little bit with this diagram, what is the middle switch for? Two buttons??

Exactly. There is a single/double module.

I don’t think they mean the double module with that diagram. Because there are other diagrams how to set up a double switch and this one is a single switch with 3 switches at one light.
But I don’t no what the middle one does in that Diagramm.

@Eeeeeediot in another thread you mentioned you have a no neutral version.

Do you know how it works, please see questions above. Thanks

Well the wireless version works with a 3v battery so I presume this one draws a similar voltage from the live wire to stay powered on.

It also acts as a router

Is this what you mean?

Yes, but to close the cycle those 3V are also applied to the bulb I think, because there are only two wires, so the current has to go through the bulb too. This could possible cause the bulb to light up a little bit.

I might be wrong.

I just received by mistake a no neutral aqara switch and i have no idea how to do the wiring. In the place i want to put it i now have a sonoff switch so I have 3 cables Nin, Lin and Lout. Does anyone knows how to connect the aqara?!

do they work as a normal switch? I mean, if it does not connect to the hub does it still work? works without battery?

"
The answer is simple and yet not so straightforward. Technically all our homes do not usually have a neutral wire. There are some of us to who open up the light switch look at two different coloured wires and think that we have a neutral wire. But 99.99% of the time this is incorrect. The neutral wire is typically blue in colour and is often present in heater and aircon switches. We usually see a brown wire which is the live wire and a green/yellow wire which is the Earth wire that is connected ot the metal bracket. So at this point, the no neutral wall switch would be the solution for our homes, right? Unfortunately, the long answer is a big NO!. Read on.

Without a neutral wire, the No-Neutral wall switch will always continue to send a small current to your light fixtures so that it can keep itself powered (its wifi receiver and modules) and continue to listen for your instructions from you or the Gateway. Unfortunately, this also means that the lights could be building up a charge from the small current. When the charge is sufficient enough the lights could flicker or blink which can be irritating and sometimes freaky if it happens after midnight.

In addition, the No-Neutral Aqara wall switches have had a lousy reliability track record and it is the reason why we have not brought in any more new stock for the No-Neutral. Let’s put it this way, we used to offer a 12 months warranty for the No-Neutral Wall switch and then scaled back to a 7-day limited warranty.

So what should you get? We recommend the Aqara Neutral Version switches. With the neutral wire, the wall switch can be self-powered. The live and neutral wire allows the switch to have a closed circuit to power itself while sending zero current to the lights. This way you do not face any light flickering or blinking. Also having sold this for more than a year, we know that this is a solid workhorse. It has a very low defect rate. Which is why we offer you a full 3 months warranty for any manufacturer defects.

Having said this you will need to work with your licensed electrician to explore if he/she would be able to pull a neutral wire to your light switch for your home. If this is not possible our suggestion is to wait patiently for a newer and improved model to be released before you make a purchase for smart wall switches.

More information as follows.
"

source: https://passionhome.sg/product/aqara-wall-switch-single-neutral-wire-required/

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I guess this is a reasonable answer except for the warranty comments. They used to offer 12 months for the no neutral version and they dropped it to 7 days. And they offer 3 months warranty for the neutral version? Why not 12 months? Why did they drop the warranty for those ones. And anyway, is it legal to sell electrical equipment with so short warranty period?

I guess that consumer rights differ country to country, but in the UK we have this: http://www.legislation.gov.uk/ukpga/2015/15/contents/enacted

I believe it allows for very small amount of current to be transferred through switch to powered device in off state, thus creating voltage divider and allowing some voltage required to keep device powered on. So this might create issues with devices that have strict on/off characteristics (like some LED bulbs) - if you do not apply enough voltage for device to start, it keeks circuit disrupted. In such case some baypass circuit is required to be connected in parallel to bulb to allow current sufficient to power the switch. This is how Fibaro or Aeotec dimmers works.

What about a capacitor? The Switch would be between the hot line and the capacitor. One side of capacitor would be floating. Alternate current would flow through the switch generating enough voltage for it to work. Probably 3 V. And current through the load so mentioned problema avoided.

Ive done no research so probably it’s not the way they manufacture them, but could it work? Any opinions?