The Shelly 1PM as well as other similar switches use a TRIAC to switch AC load, I guess. You must have minimum current, normally 5-10mA through triac to close it.
I don't know about the Shell1PM, but the Shelly1 does not need to have any load on its 'switched' circuit to enable its 'power' circuit to switch the switched circuit on or off.
The Shelly1 has a power circuit driven by 100-240V AC or 20-50V DC, or 12v DC.The power circuit can be triggered to switch the 'switched' circuit via its wireless network connections with mqtt or http commands.The power and switched circuits are isolated from each other and can be at different voltages.
The switched circuit can be an AC load of up to 240v AC at 16A, or some other low DC voltage circuit. The switched circuit of the Shelly1 can be switched on or off regardless of whether any actual connections are made to its terminals. (of course the Shelly1's power circuit will need to be connected to an appropriate power source.)
Edit: For completeness I will add that the Shelly1's power consumption is < 1W.
"The switched circuit can be an AC load of up to 240v AC at 16A"
Please, try Shelly or any other switch to turn on/off AC load 120VAC/0.01A, not a 16A. Let us know if it works. Also, Shally1 does not have an overheating protection and can't be used for encased/confined space such as small electrical box, etc.
Please, try Shelly or any other switch to turn on/off AC load 120VAC/0.01A
I have tried the Shelly1 when the switched circuit has no load whatsoever. The isolated relay can be switched on or off. (as confirmed when I then apply the load to the switched circuit, its an open or closed circuit depending on the state I set it to whilst not connected. I am presuming that as it works with no load then it would also work with a small load of 1mA.
Connecting 240volts at 16A to the switched circuit will make it toasty. Connecting a circuit consuming lesser Amps can be done in smaller enclosures. I drive a 240v 3A circuit in an enclosure about twice the size of the Shelly1 though it does have some small air circulation vents top and bottom where poking a screwdriver in will not find live voltages. The enclosure does not not even get warm.
Please, try Shelly or any other switch to turn on/off AC load 120VAC/0.01A
I have tried the Shelly1 when the switched circuit has no load whatsoever. The isolated relay can be switched on or off. (as confirmed when I then apply the load to the switched circuit, its an open or closed circuit depending on the state I set it to whilst not connected. I am presuming that as it works with no load then it would also work with a small load of 1mA.
Connecting 240volts at 16A to the switched circuit will make it toasty. Connecting a circuit consuming lesser Amps can be done in smaller enclosures. I drive a 240v 3A circuit in an enclosure about twice the size of the Shelly1 though it does have some small air circulation vents top and bottom where poking a screwdriver in will not find live voltages. The enclosure does not not even get warm.
I have tried the Shelly1 when the switched circuit has no load whatsoever
I assume you have tried to turn on Shelly1 with no load using an App, and have seen ON status on App's screen because there is no other way to confirm that load has 120VAC.
I am presuming that as it works with no load then it would also work with a small load of 1mA.
I wish I would have a Shelly switch, but I don't. If you have time, would you please be kind enough to connect 120VAC through 12K resistor (120/12k=10mA) to the switch and measure voltage across resistor. It should be close to 120VAC when switch is ON or almost zero, assuming switch has no leakage, in OFF state.
Connecting 240volts at 16A to the switched circuit will make it toasty.
The overheating protection a must. The rational behind is to prevent fire if load (120VAC to 5VDC Chinese power supply) gets short and/or switch internal current limit failed. It's a potential risk to burn your house. Of course, additional fuse between switch and load might help...
The more I read the more doubt I have about reliability of Chinese Sonoff and Bulgarian Shelly. It might be suitable for some casual non-critical application. I do not want to get involved in warranties, returns, replacement, etc. I need max. reliability, quick replace or repair.
The answer is ESP32 or ESP8266, plus latching relay to recover to last state, plus 100% isolation from AC line plus control using proven Blynk APP, Google or Alexa.
This is 1st part of my project.
please review
The second part is to make an equivalent of Shelly i3 based on ESP32/8266. If no one responds I will do it by myself.
Thank you for your time.
P.S.
Chris in SONOFF
Jun 9, 2021, 2:56 AM (3 days ago)
tome
Dear Alex,
If the Wi-Fi smart switch will be installed inside a small electrical box, it may affect the wifi signal.
1.DUALR3 hasoverheating protection, you can set the value of the voltage to cut off the power.
My note: I need set up temp. or output current- not a voltage. Shelly 1PM is set to +85C
2. We don't have a Wi-Fi transmitter switch.
3. DualR3 can't support 120VAC/10mA to 50mA. We just test the 10A minimum.
I assume you have tried to turn on Shelly1 with no load using an App, and have seen ON status on App's screen because there is no other way to confirm that load has 120VAC.
The way to confirm that either no load or a load is present on the Shelly1 'switched' circuit is to completely remove the load by unplugging it from its source. When a the switched circuit is reconnected, plugged back in in my case, then one can check it works because the switched circuit then powers up whatever is being switched. One knows the voltage and power rating of the source. I was using my own program to switch the Shelly1 rather than the Shelly App, though that would not make any difference of course.
If you have time, would you please be kind enough to connect 120VAC through 12K resistor (120/12k=10mA) to the switch and measure voltage across resistor. It should be close to 120VAC when switch is ON or almost zero, assuming switch has no leakage, in OFF state.
120 volts with a 12k resistor gives a power rating of 1.2 Watts for the resistor and I do not have a suitably rated resistor to hand.
I've not read anything to suggest any issues with the Shellys but I'm not suggesting the Shelly1 is suitable for whatever you are endeavouring to achieve. I was stating the facts of the Shelly1 as it seemed at odds to what you were inferring as regards the Shelly1PM. The Shelly1 is mostly used in mains lighting circuits where its seems to be well received and I've not read anything to indicate it gets hot and indicating it could be a fire hazard. I would not expect to continually use the Shelly 1 at its maximum current draw rating without making sure steps are taken regarding heat dissipation. As I said previously at lower amps the Shelly does not even get warm as measured by applying one of my pinkies to test for heat. Using a cheap Chinese power supply for the source would be a concern undoubtedly, but I don't get the impressing there is any concern with the Shelly1. I would not doubt that a camera, or whatever, can be switched on or off by the Shelly1 as long as the voltages and current draw are from 0v 0A to 240V 16A.
As some switch box pattress boxes are metal and that is where the Shelly is often location I guess there maybe some wifi signal degradation. My Shelly1 enclosures are ones I 3d printed and I do not have any issues with wifi signal strength.
As the Shelly1 is 'switched' by mqtt or http messages then one can use whatever programming tool once desires, C, C++, Python, MicroPython, CircuitPython.... The Shelly1's power and switched circuits are isolated from each other. However no doubt you can also choose to use your own latching relay and your own circuit if that better suits you. Whatever floats your boat.
A few clicks and a couple of days will surely make your wishes come true. And if it does not meet your aspirations Shelly donations are gratefully received by any forum member I would think. 😎
As the Shelly1 is 'switched' by mqtt or http messages
I forgot the mention that the Shelly1 can also be connected to a manual switch. This switch in not connected to the 'switched' circuit, but is a means of mechanically indicating to the 'power' circuit it should switch the switched circuit on or off.
So, what am I missing here? Is the problem that the Shelly 1PM will not turn off the power to the camera because it is too low of current? That's not right. I uses a relay. That is a physical disconnect. Power will not flow if the contacts are not touching. Current should not matter although low current will be better for the contacts.
So, what am I missing here? Is the problem that the Shelly 1PM will not turn off the power to the camera because it is too low of current? That's not right. I uses a relay. That is a physical disconnect. Power will not flow if the contacts are not touching. Current should not matter although low current will be better for the contacts.
This is Grate! Exactly what I need-a RELAY. Is the relay part of shelly 1PM?
According to picture bellow relay's contact is internally connected to L (phase). Is it possible to cut out this connection and use contact to switch DC load? What are two large green parts on right side of relay? Thanks for help.
This is Grate! Exactly what I need-a RELAY. Is the relay part of shelly 1PM?
Not sure if I am responding to sarcasm but, yes, all the shelly devices listed under relays have relays. Only their dimmers use triacs. Here is a shot from the other side of the board. No triac in sight that I can see. Product name is on the silk screen.
According to picture bellow relay's contact is internally connected to L (phase). Is it possible to cut out this connection and use contact to switch DC load?
If you power it with 24-60V DC, you could use it as is assuming you make sure you have the correct voltage for your camera. Otherwise you would need a DC power supply. You would need one either way really.
I see the Shelly1pm is somewhat different than the shelly1 (which also uses a relay) in its wiring so I put it up here for reference, especially as the manual switch arrangement appears to work differently.
I see the Shelly1pm is somewhat different than the shelly1 (which also uses a relay) in its wiring so I put it up here for reference, especially as the manual switch arrangement appears to work differently.
My guess would be that the L for the switch is past a full bridge rectifier and a resister. I wouldn't want to be breaking mains voltage if it was using AC, even if the current is low. Makes sense in my head at least. It also makes sense to just share the neutral and not even run it through the device.
Interesting that the ditched the jumper for DC voltage though.
Edit: Nope, just saw the solder blob bridging the L and L1 connections. Not so sure about how I feel about that resistor instead of a fuse.
According to picture bellow relay's contact is internally connected to L (phase).
It just now hit me. It is only connected to the L phase when the relay is closed. That is a bad picture and the connection up from 0 should be jumping over it. It does not connect there.
just saw the solder blob bridging the L and L1 connections.
From that I assume that the Shelly1pm's power and switched circuits have to be the same voltage? A different beast to the Shelly1 where one can power the shelly1 with 12v to switch a 240v switched circuit or vice versa. (they can also be the same voltage of course).
I suppose I should not make assumptions, and this shows that one must be careful to read and understand the Shelly module one intends to use as illustrated by @roman47 who seemed convinced the shelly1pm used triacs whereas it appears to use a relay like the shelly1. And note the shelly1 would not work without a neutral connection (AC) or a +/- connection for DC.
This is Grate! Exactly what I need-a RELAY. Is the relay part of shelly 1PM?
Not sure if I am responding to sarcasm but, yes, all the shelly devices listed under relays have relays. Only their dimmers use triacs. Here is a shot from the other side of the board. No triac in sight that I can see. Product name is on the silk screen.
According to picture bellow relay's contact is internally connected to L (phase). Is it possible to cut out this connection and use contact to switch DC load?
If you power it with 24-60V DC, you could use it as is assuming you make sure you have the correct voltage for your camera. Otherwise you would need a DC power supply. You would need one either way really.
just saw the solder blob bridging the L and L1 connections.
From that I assume that the Shelly1pm's power and switched circuits have to be the same voltage? A different beast to the Shelly1 where one can power the shelly1 with 12v to switch a 240v switched circuit or vice versa. (they can also be the same voltage of course).
I suppose I should not make assumptions, and this shows that one must be careful to read and understand the Shelly module one intends to use as illustrated by @roman47 who seemed convinced the shelly1pm used triacs whereas it appears to use a relay like the shelly1. And note the shelly1 would not work without a neutral connection (AC) or a +/- connection for DC.
@roman47who seemed convinced the shelly1pm used triacs whereas it appears to use a relay like the shelly1. And note the shelly1 would not work without a neutral connection (AC) or a +/- connection for DC.
Yes, I was convinced that Shelly 1PM and other similar switches use a triac- based on responce from Sonoff (see above) and the fact that Shelly does not specify the smallest load current. I'm glad they use relay.
I do not know yet how, but will try to disconnect relay contacts from the Phase and output screw-terminal "N" from the Neutral, than reconnect "N" screw-terminal to second relay contact. It will free up relay contacts to control DC or non-120AC loads while Shelly 1PM itself receives power from 120VAC.
I wonder if a serial port can be used to drive an external relay. I asked Shelly support but did not receive answer.
Sorry, you seemed fairly stubborn in previous comments and I actually found it hard to believe the problem was that simple. I thought there was a good possibility that I misunderstood the issue hand.
I do not know yet how, but will try to disconnect relay contacts from the Phase and output screw-terminal "N" from the Neutral, than reconnect "N" screw-terminal to second relay contact. It will free up relay contacts to control DC or non-120AC loads while Shelly 1PM itself receives power from 120VAC.
That is not how this works. The 1PM draws power from the same source and you need both present for it to work. You could just get a relay for much cheaper if you want to design it yourself but all that work defeats the purpose of the relay. Not to mention I don't think that would even work. If you just connect the relay to 120 and have the switched terminal connected to your DC power supply, it will work. I don't think it is any more complicated than that. You should never be switching anything by the neutral. Hot should always be the one shut off and on.
I wonder if a serial port can be used to drive an external relay. I asked Shelly support but did not receive answer.
I believe that is only for powering it while reprogramming the microcontroller with your own custom code, I doubt it will power the relay safely/isolated from the main supply.
To be honest, if you are having this much trouble with some basic understanding of electronics, I would recommend not messing around with mains power. It can be dangerous. That recommendation is really for your safety.
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