Hello,
I am looking for a device able to work with 24v AC and if possible be used for other voltages.
I am testing right now with the esp-01s v1 but appart that I can not control the button, the device comes without a case.
I wonder if there is something like sonoff or shelly 1 but allowing low AC voltage.
TIA
I have usually just attached a mains voltage relay to provide volt-free contacts and stuff the bits in a Box.
You can buy an ac-dc transformer and connect your relay to that. I have done this before with a wemos d1, a relay board and a small ac-dc 5v power supply. Bought all of it from aliexpress for about €6.
Something like this maybe:
Power supply
Yep, I’ve done that as well 
This is just after I tested and before I put final insulation and more hot melt, the putting the lid on.
It runs my Waste Collection Indicator.
This needed two buck converters. The First a 240vac to 5vdc then Another to get down to 1.64vdc
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I have been successfully using one of these with some 24VAC heating zones: https://www.amazon.com/gp/product/B01NB0XJ0F
Neat, and ready with 4 (individually switched ???) single pole double throw relays 
I assume you use MQTT to access those ?
Mine has ESPHome loaded on it and I built a small power supply board to power it from the 24V transformer that feeds the boiler and valves.
Thanks, I will google for infomation about that.
I will google for that too, I am not sure if I have enought electric knowledge
So you can control 24v Ac with that board? the specifications of the relay says: 10A 250VAC & 10A 125VAC. Does it work with 24v also?
Thanks
These are maximum limitations
250vac is strenuous as its an rms value, it actually peaks at 353v
So this is an indicator of its ability to switch voltage without compromising a path (say) to earth
The 10A is also a maximum and indicates a maximum sustained current carrying capacity (this is also rated for the end of life value when the contacts may have become slightly pitted).
So a switch at that rating could easily be used to switch (say) 500mV and 0.01mA (ac or dc)
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A Sonoff SV would fit the bill: https://www.itead.cc/sonoff-sv.html
It has relay on board for around $5, and accepts 5-24V DC input. If you want to run it off the AC voltage you could power via a AC-DC bridge rectifier. You can also isolate the power supply being switched from the power supply running the board.
Can be flashed with usual ESP alternative firmwares (ESPHome, Espurna, Tasmota).
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Yep, works fine for switching 24V. Powering it is another matter though, it requires 5V DC. I used a bridge rectifier and some capacitors to produce about 32V DC from the 24VAC, and then used a switching regulator to drop it to 5V. Works great. It would be fine running off a 5V regulated “wall wart” too.
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That sounds pretty interesting. I knew about that board but not thought about switching AC-DC. Maybe it would be enought if I switch its input and its output back to AC. Isolate the power supply would be much for me right now. Thanks
I am going to buy the board, powering wouldn’t be a problem because I have 220v in the place so I can power it easily. I have this board but I am not yet able to make it run with another firmware. So I will try yours, I hope it will be easier 
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Hello again guys, It’s me again. I couldn’t get the LinkSprite sent to where I live but I found this https://www.itead.cc/sonoff-4ch-pro.html Would you think that it will do the job? It is probably not the cheapest solution for only one channel but it maybe for more and I don’t need to be adding extra component as my knowledge in electricity is limitated to videotutorials. Also I am used to flash sonoff devices which maybe helpful. TIA
We’ll you can use it, but if I were you I’d just buy a normal single small sonoff like this.
With these you can choose if you want the input to be 5v DC, 12v DC or 220v AC
Thanks for you reply @SvenBosma. The thing is that I need 24v AC. I know that there is another one which work with 24v DC but I haven’t found one for AC. I had a look at the one that you told me and I see the same, low voltage DC but high voltage AC. Do you think that it will work with 24v AC? TIA
No, this won’t work with 24AC, I thought you said that there is also a 220AC input nearby. Maybe buy the link from my last post and use this as a input device
Thanks for your reply again @SvenBosma Yes, I do have 220AC input nearby but I need to switch over 24AC. That is the reason that I found the 4ch pro useful because it is powered independent from the relay. Is the one you shown me to?