SuperHouse #34: Science or sorcery? Sonoff T4EU1C no-neutral wifi touch switch 

This video perfectly shows the difference between a RU-vidr and an engineer on RU-vid.

I thought I’d just watch a few mins, next thing I know it’s over. Well put together and interesting, thanks.

This is actually very smart, I was pondering an alternate route. When relay is off, use the potential, when it's turned on it also runs the line through a transformer letting it parasitically live off the power being consumed by the attached through a secondary coil

I was trying to find the time myself to figure out inner workings of the T4EU1C, so thank you very much for the brilliant explination!

I got one of these switches from another company and was dumbfounded by how they work without neutral. This video explained it very very well, thank you!

Thanks, I've been wondering about this new sonoff for a week now.

Thank you very much. As an electrician I have installed a few different smart switches and was very confused by no-neutral. Thanks for clearing that up.

oh yes a 40 minute video from my fave youtuber , cant wait to finish work tonight to settle down to watch this

You explain things really well. Thanks for that. It helps me make decisions on what to use when and where. 👍

IMPORTANT UPDATES. 1) Many people still have trouble with the touch switch. The reason mine works is probably due to replacing R10 after I damaged it. I don't have a second unit to test with, so DrZzs and others are working on verifying this right now. I'll update the web page with info about this. 2) YES, IT WORKS WITH LEDs. That seems to be the #1 question about this video! Controlling LED lighting is actually the most common use-case, and it's what this is primarily designed to do. I've tested it with an LED downlight and it works just fine, but needs the anti-flicker unit installed so that the Sonoff can get enough power to run itself. I didn't bother showing this on the video because I thought it would be the most obvious use for it, so there'd be no need to show it. Sorry! I should have included it anyway.

Great Video Jon. Always look forward to seeing what you come up with next, you always cover things in good an clear detail. I did figure the anti flicker was a given for leds/ cfls etc. Also Nice UAV Futures intro ;)

Can't believe I have only just got round to watching this one! Great write up on how the magic works!!

Epic effort, and well-timed too! I've just been considering the very real problem of what to do about the 'lighting conundrum' in my home renovations. I've built my own ESP8266 shield for power and RGB lighting control for the kitchen and other places so this rounds off the project nicely!

Great explanation! Learn so much watching your videos. Thank you for putting together great educational videos so we can understand all of this.

Great vid. I particularly like the nod to Stu @ UAV Futures!

thank god for this video. my electrician told me he couldnt bring a neutral down to the sonoff switch i got but i got new sonoff TX that requires no nuetral and thank god its not a gimmick and is actually legit. thanks man!

That procedure worked perfectly fine for me, thanks a bunch ! Note that taking the ground on that small capacitor ended in shorting VCC to ground for some reason, that was solved by reflowing it with hot air. The easiest way to get ground is probably on the connector on the back :)

brilliant video... you reminded me of stuff I learned decades ago with electronics and forgot about! Saw a different video and it was so aweful watching someone try to explain how the switch worked without having a clue! Interestingly, I built my own switched socket using a sonoff mini... needed to build it this way as I need the socket to be covered and waterproof! BUT the neon indicator didnt work and I realised why because of what you reminded me of in the explination of the voltage potential. thanks

Thank you! Plenty of knowledge, good inspection after all

Great work. I'm so glad I don't have any switches that need this beast. Flashing is a real chore.

A super analysis and tutorial. Thank you!

Very interesting explanation. Thank you.

This video is GOLD, very good explaination if the L wire only trick, super nice tipp for cool terms baudrates and also to the last issue: I have experienced that many times and also came up with a very similar way of entering bootloader mode on the touch switches! I just always thought I was alone with the issue 😅 Thanks for the great video

Amazing video !

Great video! Really interesting content.

One word for you you are a genius

stumbled across this YT channel. i just discovered a gold mine! :D

As someone who's got a 1920s house with no neutrals, I very much appreciate this video and in depth explanation!! Now if there was only a DIY version of this to power a Wemos...

Clever ! Thanks

Very well explained, thank you. Just one niggle in my mind though. My whole house uses LED (Mains) bulbs and one dimmer for LED bulb, so how would this device perform, bearing in mind the triac may interfere?

Thanks for a great explanation Jonathan. I flashed it without the reset. It worked. I got the Wifi AP, loaded the UI, was able to control the light through the Tasmota UI, but I could not get the Touch button to control the light. I don't know what could be different. Still has be stumped.

I bought the T1s when they first came out with the idea of re-wiring to fit them. I never got around to that - instead I used a battery powered servo to flick the switch. Now it seems I can swap those out for these! I guess I'll find out if they work for the 2 way switch arrangement (hall lights upstairs & down controlled from a downstairs switch & a an upstairs switch!). £12 delivered seems about the going rate!

Excellent video! Very understandable and thorough. Thanks for making it!

I thought it was going to use the voltage drop across a small value resistor in series with the switch. But their idea is clever, it works well regardless of the load size.

Brilliant.

@SuperHouseTv: Which valuedoes the R10 have? I unfortunately damaged mine too.

Hello, thank you for the great video full of helpfull information! For me only one question left: how much power it cunsumes via antiflicker device? As I understood, 0.3A is a maximum, but what about real consumption?

This guy is really good

Sounds like you have worked out my old problem with Version one of the units. Now the mini will it work the same? I did the same with the button a couple of years ago. I ended up going to Espurna instead of Tasmota.

Hi, I noticed that after flashing the tasmota image the wifi LED works only when the circuit is closed (the bulb is ON)(see @40:00). Why is that? and how to fix it, I mean the led helps as a night indicator.

Great video, wonder if sonoff will bring out rectangular versions of this.

Great in depth stuff Jonathan, nice to see we have a bleed resister over those caps, I have in the last few days flashed my first sonoff basic with the latest Tasmotta firmware, however no matter what I do I can not get it to work with Alexa, someone has said that it no longer works, do you know anything about the matter ? thanks Stuart

Jon has his Louis Rossmann style cavity search gloves on!!!!!!!!!!!

Hi Jonathan, Dont suppose you have figured out using two of these switches with one light like in an upstairs downstairs 2way switching arrangement. Great vids and many thanks for your help

Great Video!!! Question: does the 50 hz oscillation dims the amount of light that the bulb outputs? Doesn't it work like a PMP diming the light?

hey mate, great work! just curious if you have made any videos on ceiling fan automation?

Excellent Thanks or that Jonathan - now, I'll still waiting for my Itead sample - the original Itead T1 UK version definitely does not work without neutral - and now you;ve sparked me off, I have a oair of ZemiSmart equivalents - one works perfectly - the other comes on and stays on, with or without the supplied capacitor (without it runs at half-power). I tested 6w LED E14 lamps - in the UK of course, on 249v mains power.

Thanks for great vide @superhouse. Can I ask you if you would do a video about how to make a low-pass filter for Sonoff Touch ? As some of mines are ghostswitching (and it's not because of mqtt) I would like to give it a go, but not really sure how to do it on that board . If you could do that, that would be absolutely terrific! Thanks a lot for your time!

Nice video ! Also played with this switch like a month ago and I like it a bit more than Minitiger switches U may also check those the power logic on them is different, but they are much easier to flash and also have the RF433 chip onboard so u may use that one too (useless for me though) But the big plus for this one is that I ripped off the front plate and cover and put instead an LCD with touch the power board here can produce enough mA to drive that, so all in all I like it but it only comes in 1 way gang and Minitigers can also be found in 2 or 3 way that's a bit sad but fine for now as I have the best of both worlds. DO recommend this 1 way switch if u need some more mA to power up some other logic and u have only one bulb to control :)

Great video just getting into smart wiring etc after being an electrician for 30 years, we never used to run a neutral to the switch as this was bad practice(to stop your diyer switching the neutral instead of the line conductor) however in the past 5-10 years wiring a neutral to the switch is the norm,it's also alot easier when it comes to testing the installation .,could these sonoff be wired in series to a 230v coil controlling a contactor for larger loads?

Hi! Great video! thanks... What is relay type used in main board?

4:16 with the Tasmota firmware the LED is not ON when the light is OFF, is that configurable? (7:49 normal operation)

@ 27:20. If you are using a regular incandescent (without the series capacitors) you are ALSO using extra power. You are using this extra power to power the ESP. My guess is that it is not much different, because the smart power control chip in the smart switch will pull as much power as it needs to keep the 3.3V and/or 12V regulated.

just like magic, now i only need to wait for itead to put out a sonoff mini no-neutral. So i can "smart" all my house existing lights while using the old switch panels. I don't know if anyone like me, hate the feeling of touch switch panels. It just don't fit my house's style

Very good explanation. Nifty technique. 300mA x 240V=80Watt extra use. That's substantial

Hi, question, From when it's trying to take power in case of 3 gang module? All bulbs or just the one in L1?

Ok please forgive my limited electronics knowledge but I have a question: why wouldn’t they have just placed a transformer in line with the active. When the switch is closed the transformer coil would induce a magnetic field across the secondary that they could use to run the circuitry? Is this not an easier option than pulsing the output? Cheers MB, 16 Perth

good video. I would like to know. could this also be done with a sonoff mini and which capacitor should i have?

Do you think two of these in series would work? L-out from the first into the L-in of the second and then to the light? Is there enough power left through the 50hz triac to power a second t4eu1c?

I was thinking about getting into automation of lights and instead of automating bulbs and having physical switches turned on all the time smart switches make more sense and lights can still be turned on or off manually. But I would like to keep the switches physical (as in rockers, not touch points) because it works even with gloves, when hitting it with something else than hand etc. Aqara makes switches like that but they blink the buls every couple of seconds because they don't have the antiflicker capacitors (and I have no idea how to calculate those). So I was thinking if Sonoff switches could be hacked with a physical button instead of a touch button. From this video it seems the only necessary part is tripping the GPIO0 to turn on or off the relay (I don't know if momentary or latch is needed but I can find that out). But you mentioned soldering to GPIO0 is difficult so now I'm kinda undecided. By any means, do you think it could work? P.S.: I would need those switches without neutral, my wiring is old and I have concrete walls in an apartment so pulling more wires through is not an option unless I want to mess up the whole apartment.

Thank you, about 2 years I would like to do this Do you think we can clone this little circuit with just a triac and power another basic esp8266 module? (With a 220v -> 3.3v) Thanks a lot for this video :)

Perfect explain !!! Very good job !!! Well done !!! Does anyone know where can we found the ic lp3669 or what else can I use ? I have already 2. Switch with burn that ic.

hi thank you for the video. i have a question about triggering the triac. Since its triggering the triac after mains voltage is above some treshold. How the circuit knows when to trigger. Is there a zero cross detector.

Great video thanks. But what a big soldering iron you have

Just curious, could you use the cap sensor to bring gpio0 low and just solder onto reset?

what is that blue component (right side of the fuse) used on mains potential sir?

I got a Sonoff SA-025-2.4G-1C with a single capacitor without the resistor. Does the stored capacitance on the resister not discharge itself across the load of the lamp over time? Thank you.

Hi can you make a video about the Sonoff iFan. I’ve read mixed things about fan control and being bad for the fan motor / potential fire hazard.

0.3amps at 240v is 1.7kw per day, 670kw per year, at about £120. That could be per light. Ouch. Great video on how they work.

Would that anti-flicker unit fit in a standard UK ceiling rose?

is the flicker free element available for purchase separately ? cant seem to find it onlien

I've been pretty successful with just using bluetack to attach wires for flashing. Not sure if it'd work at this scale though. Maybe a drop of superglue in case one wants to avoid soldering. Another tip I have is to use wire wrapping wire for this type of wiring. It's much less intrusive as its extremely thin and requires less heat to get the solder joint done.

Hi there, Just installed the TX T4EU1C with 3 LEDs they are P20. My problem is it works for about 5 seconds then turns off. I thought it maybe to much wattage so I reduced to two....still same works for only 3-5 seconds. any ideas? do I need to wire in the anti-flicker device? YES and all working...Thanks

Hi, great video.. I have sonoff touch no-neutral 2ch. On one channel i have connected LED light, on second FAN.. but once i switch fan on, switch loose power.. I will try replace LED bulb with normal bulb, and try it again with and without "load capacitor"

i have been thinking... why does ITEAD need the relay at all ?? The triac is used to interrupt the LINE in order to steal power. Does that not imply the triac can be used to switch the load off entirely ? In fact, since it is synchronized to the 50 Hz zero crossing it could be used to phase delay the leading edge of the voltage waveform, thus it could also function as a dimmer (at least for incandescent and some dimmable LED's). What am I missing ?

It's worth noting that he's using a battery powered oscilloscope for the analysis. To do this with a mains powered oscilloscope differential probes should be used for safety. (I've learned this by watching RU-vid so please correct me if I'm wrong. I don't own either differential probes or a battery powered scope.)

Can I clarify how the anti flicker device is connected to the load? Is it as simple as connecting one end to the live and the other the neutral? Also does the direction matter? Thank you.

Brilliant video! I was scratching my head for days wondering how they did it. One question, why use the mechanical relay when the triac alone can cut the power to the light? And secondly, if the anti flicker device can flow 300mA at 240V, that's 72 Watts, which is more than twice the consumption of an LED lamp. Does it flow this much in practice? How does it not overheat?

Great explanation. I love your videos! One question: Why did you call it "active in" and "active out"? Shouldn't it be "*live*" -- that's what the "L" stands for on the label: L = Live; N = Neutral! Is there a different terminology where you live?

Good video .. Please tell me what is R12 and C14 in board? How many ohms? Why not connect directly pad touch to pin IC ? ( just like ttp223 Schematic!!)

Nice video! About five years ago, I tried to build a non-neutral circuit like that, and I did. But it did not work for me because this triac technique only gave me 100ma maximum and my circuit with wifi required more than this. So I would like to know how this circuit can delivery more current. Is there any other video or information source that explains this magic? Is it possible to record a new video about this theme? Thanks in advance, the video is really very useful.

Could you explain on the flickering of lights, I have a three button smart switch with a N connection on it. Two of the room lights work perfectly with No flickering, but the first switch flickers on off and off. What I cannot understand is why two rooms work perfectly and one room has this problem, all bulbs are LED.

Very good explanation ! Is it so that the triac is in series with the relay contact ? What is the purpose of the relay if the switch can control output power ? I missed something probably...

Hi, I would like to ask your help, how should I connect Sonoff Mini if I don’t have nautral wire in My switch? Unfortunately I have Gira glass design switch and shutter and I don’t want to replace them. Thanks Laszlo

Was that soldering iron a High School graduation gift? 😁🇦🇺

Hopefully they come out with an AU version. Please post a video if they do 😊

My question is regarding the capacitor and resistor. Those capacitors are connected to the bulb, wouldn't the discharge over the bulb and actually, there is no need for a resistor?

How much power can the high voltage side supply? Could I power a Pi Zero with a small touch screen for example? What I want to do is build a small unit that would replace a standard light switch and hack something like the Sonoff to power the Pi and the screen for a Home Assistant dashboard.

hi super house, can this switch use for ceiling fan ?

Hey Jon, I know we've been saying 240V for ever, but I believe the standard for Australia/NZ changed to 230V in 2000. (Except Qld which is transitioning and WA)

What is the real power consumption when running trough the anti flicker device?

Hi, can this be used with low power inductive loads like a ceiling fan or bathroom/kitchen fan. I'm looking for a timer switch to keep the fan running for a given time, and I could find mechanical ones only. I was thinking maybe this one would work. My socket has only 3 wires, live, switched live and ground. I checked manual of this switch, but it does not specify anything about inductive loads or fans. Did anybody try?

Any reason you didn't scrape the via that's on the other side of your resistor instead of the middle of the track? Would give you a slightly better pad for soldering the wire to .

flashed 3 of these I took my zero volts from the connector on the back of the board and touched the other end on R10 while booting all 3 working 100%

The wasted power with the anti-flicker unit is only when the load is active, with the load inactive the power used should be basically the same as with an incandescent bulb (e.g. dependent primarily on the Sonoff's power draw). Given that the loads that would need it are already much lower power than the incandescent - it seems a reasonable trade-off.

The trick of using the capacitor as anti flicker is nice, but in long term it is pretty expensive... A simple calculation shows that it consumes another 70 Watt when the load is on: 0.3[A]*240[V]=72[W], and this will usually be added to a bulb that consumes only 12-15W (standard LED / Florescent bulb) - so it increase the electricity usage by ~5 times (!!!) Please correct me if you think that I am wrong :)

I noticed these seem to be in the EU form factor. Does Itead have one in an AU form factor yet?

Does anyone know if there is a zigbee compatible switch that works like this? (i.e no neutral wire required to switch the load)?

Thanks for the nice video ! Is it possible to use this switch to control a serie of led lights ? If yes where you put the anti flicker device ?

very interesting video. Is there any way to use a sonoff basic with no neutral, maybe with an external circuit home made?