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Hello from cold Russia.

1)Don't use the grounding wire to connect N pin on your wall switch. If you don't want to win Darwin award. 

Look at the first picture.

2)Use capasitors to connect the switch and the bulb. 

Look at the second picture.

C1 - Capacity. Metal-film capacitor for 400 volts.

It works as a "quenching capacitor" or "resistance". In order for the "part of the current" to remain on the switch and feed it, in the switched on position of the key.

C2 - Capacity. Metal-film capacitor for 400 volts. 

Works as a "bypass" resistor. Serves to ensure that energy-saving gas-discharge or LED lamps do not blink (from the current passing through them supplying the switch) in the off position of the key.

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2 people have this question


To Marius Herta.

You used 4.7 uF capacity as C1. 


What kind of bulb did you use? It seems to me it is a gas bulb. Which is about 10-15 Watts. 

I guess - you've got to use 2,2  uF capacity in case that is 15 Watt bulb not 4.7.

Use the rigth capacity.

2. I do not see C2 on video. There is no C2 in the wiring of the bulb. 

Install the C2 capacity to ensure the bulb not to blink in the OFF position of the wall switch.

Hi sshRage, May I know can the C1 connect to the L2 instead L1? And what will be the connection if I have more than 1 smart switches in same row? Can single C1 and C2 handle for all?


I have setup three Sonoff 2nd gen switches. With different capacitors, basically I have two switches with C1 being 1uF, one 1.5uF. One LED bulb C2 is 0.47uF, without it it flickers. For second switch I have two LEDs with C2 being 1uF. To avoid weird glitches, like one lamp not turning on or one flickering other not, I have to use both LEDs same brand same wattage. Last interesting thing is that Ikea LEDs don't need C2, since they don't flicker.

So in general all works like charm, but there is two bugs. One is phantom clicks - sometimes light turn on by itself and it is happening randomly with all three switches. I don't know if it is related to this type of connection with capacitors or it is some bug with Sonoff switches. Another bug I noticed is that switches sometimes randomly goes into pairing mode for about 5 min, then connects back to WiFi.

Anyone have experienced this kind of bugs?

Sorry if this is the wrong thread, I'm a newbie, any idea how to wire a sonoff mini into this (see attached)?


To Stanner - yes, it dos not amtter if you connect C1 to L1 or L2. It'll work in bothe cases.

To Aliens - please check that behavior without C1 C2 solutions. Actually I've exprienced those problems - because of SONOFF cloud problems. Thats why I reboiled all switches with my own firmware. And I use domoticz on OrangePI as my central server instead sonoff chineeese cloud.

To James Taylor - It seems to me the hole topic is about your question. How to wire it not using ground wire as neutral.


Would the same trick work for sonoff mini? As I'm missing neutral wire too :(


I think yes, it will work.

But there is another solution in case SONOFF mini. You can do all the wiring on the celling. If it is possible in case of your room/flat/house...

Well, I could connect it on the ceiling but would not have a way to connect to the switch on the wall or am I not understanding it correctly? Are you able to provide any schematics? I have a standard with no neutral wire config.

The two wires from the switch on the wall terminate in the ceiling box.  Install the mini in the ceiling box and connect those switch leads only to the switch input on the mini.  That is exactly what it is designed for.



hah not doable with current cable configuration :( please remember I have only one live wire in the wall switch. Your picture presents perfect connection :)


You have a live wire in the wall switch because it is tied to the hot wire in the ceiling box.  The hot travels to the wall switch then back to the light bulb.  (see the graphic below)  When the switch is closed the light comes on.  Disconnect the two wires from the wall switch from all other wires in the ceiling box then connect them to the switch terminals on the mini.  You have everything you need in the ceiling box.  1. Hot from the main panel, 2. Neutral, 3. Hot to the light socket, 4. Neutral to the light socket, 5. Both wires from the wall switch.


This does not work with a clasic wiring. The neutral goes from the bulb directly from the electric box thru a wall/ceiling. In the switch box is only the live wire that comes from the electrical box and goes to the bulb.

Yep, that's my problem too :/ that's why I used the method mentioned here in the first place while connecting T1 switch. I'm hoping that it might fit behind classic switches that I have here in Poland and use it the same way as T1.

Well I have never been to Poland and I have also never seen an AC circuit where single conductors leave a main panel going to different places.  In general sheathed cable (Romex) is used containing a hot, neutral, and bare ground wire.  It feeds from the panel to a junction box somewhere and from that box to the switch and light socket.  The Mini goes in that junction box.

Are you saying a single hot wire comes from the main panel to the switch and a single neutral wire comes from the main panel to the light socket?

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