3 ms·

I'd be more worried about the 2A solid state relay, seems way underspecced for a typical 10/16A plug.

by aulin 3y ago

deleted 3y ago
[deleted]
jacquesm 3y ago
Have a look at what is inside a typical blister packaged smart socket and you'll never use one again.
- aulin 3y ago
  I've used tasmota pre-flashed Athom 16A smart plugs with discrete success. According to this video https://www.youtube.com/watch?app=desktop&v=FWQe4RFgY1s https://www.youtube.com/watch?app=desktop&v=FWQe4RFgY1s at least the relay is the proper one and wires seem beefy enough. Unfortunately they tend to die prematurely for some LVDC regulator problem.
  - jacquesm 3y ago
    Both the relay and the wiring in that particular smart plug looks to be up to spec, going by the markings on the relay and the apparent wire thickness. At the end of the video he does an insulation test as well and it passes with room to spare. There even is a basic surge protection in there (the big blue disc). I would have liked to see the circuit board airgapped between the HV lines to reduce the chance of creep if it ever gets humid, but for dry applications indoors this should be ok. I didn't see a fuse and I would have liked to see a small inductor to separate the HV from the LV section but that's expensive so many brands choose this kind of directly coupled system. R1 (the high wattage resistor next to the relay) and the two 400V caps are doing the heavy lifting there and even though that works I just don't like having electronics directly coupled to mains voltage. The 'Sonoff' devices do this better. I've done a similar teardown on KaKu, Tuya and Shelly products and only the latter were - in my opinion - acceptable from a mechanical and electrical design perspective. The Tuya stuff was absolutely terrible (and required a server in China to have access to stuff in my home which will never happen), the KaKu ones are confusingly labelled (but if used at the lower of the two labelings probably safe) and much lighter in construction than the website suggested. The Shelly stuff is simply solid and comparable to the one in this video and doesn't require any cloud services. So that's what I went with. Bonus because it integrates seamlessly with HA.
- deleted 3y ago
  [deleted]
squarefoot 3y ago
True, especially if bought from Aliexpress, Amazon, Ebay or similarly unreliable source: most solid state relays sold there are relabeled fakes claiming higher specs than their actual one. https://protosupplies.com/inferior-counterfeit-fotek-ssr-25-solid-state-relays-on-the-market/ https://protosupplies.com/inferior-counterfeit-fotek-ssr-25-... https://www.eevblog.com/forum/reviews/warning-dont-buy-fotek-solid-state-relays/ https://www.eevblog.com/forum/reviews/warning-dont-buy-fotek... Buy parts only from reputable sources, especially when safety is involved, which is the case with everything that is connected to mains voltage.

I'd be more worried about the 2A solid state relay, seems way underspecced for a typical 10/16A plug.

by aulin 3y ago

I'd be more worried about the 2A solid state relay, seems way underspecced for a typical 10/16A plug.

deleted 3y ago

[deleted]

jacquesm 3y ago

Have a look at what is inside a typical blister packaged smart socket and you'll never use one again.

aulin 3y ago
I've used tasmota pre-flashed Athom 16A smart plugs with discrete success. According to this video https://www.youtube.com/watch?app=desktop&v=FWQe4RFgY1s https://www.youtube.com/watch?app=desktop&v=FWQe4RFgY1s at least the relay is the proper one and wires seem beefy enough. Unfortunately they tend to die prematurely for some LVDC regulator problem.
- jacquesm 3y ago
  Both the relay and the wiring in that particular smart plug looks to be up to spec, going by the markings on the relay and the apparent wire thickness. At the end of the video he does an insulation test as well and it passes with room to spare. There even is a basic surge protection in there (the big blue disc). I would have liked to see the circuit board airgapped between the HV lines to reduce the chance of creep if it ever gets humid, but for dry applications indoors this should be ok. I didn't see a fuse and I would have liked to see a small inductor to separate the HV from the LV section but that's expensive so many brands choose this kind of directly coupled system. R1 (the high wattage resistor next to the relay) and the two 400V caps are doing the heavy lifting there and even though that works I just don't like having electronics directly coupled to mains voltage. The 'Sonoff' devices do this better. I've done a similar teardown on KaKu, Tuya and Shelly products and only the latter were - in my opinion - acceptable from a mechanical and electrical design perspective. The Tuya stuff was absolutely terrible (and required a server in China to have access to stuff in my home which will never happen), the KaKu ones are confusingly labelled (but if used at the lower of the two labelings probably safe) and much lighter in construction than the website suggested. The Shelly stuff is simply solid and comparable to the one in this video and doesn't require any cloud services. So that's what I went with. Bonus because it integrates seamlessly with HA.
deleted 3y ago
[deleted]

squarefoot 3y ago

True, especially if bought from Aliexpress, Amazon, Ebay or similarly unreliable source: most solid state relays sold there are relabeled fakes claiming higher specs than their actual one. https://protosupplies.com/inferior-counterfeit-fotek-ssr-25-solid-state-relays-on-the-market/ https://protosupplies.com/inferior-counterfeit-fotek-ssr-25-... https://www.eevblog.com/forum/reviews/warning-dont-buy-fotek-solid-state-relays/ https://www.eevblog.com/forum/reviews/warning-dont-buy-fotek... Buy parts only from reputable sources, especially when safety is involved, which is the case with everything that is connected to mains voltage.