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0 pointslloeki2y ago0 comments

Sounds like a call for a steady soldering hand.

I'm that close to do the same for my child's nightlight: just shunt power around whatever is opening the circuit and drive it with a Shelly plug.

(Okay the grand idea would be to ultimately put an ESP32 between the control unit and the three buttons, so that I can both operate it manually yet have full control of the thing; not the least because if you cut power it resets its state to a static white light. Never done that so that'd be nice way to acquire the skill without much risk to that super cheap device)

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ClumsyPilot2y ago

It’s antithesis of ‘sweet spot’ between dumb and smart.

Thing should either be dumb and do everything you want with a button, or smart and then at least you get programmability.

For simple things like lights it’s usually better use of time to buy Yeelight nightlight and then you get to control it through HomeKit:home assistant/their app.

lloekiOP2y ago

> It’s antithesis of ‘sweet spot’ between dumb and smart.

You mean the soft buttons? yeah it's nuts, not the least because since it's reacting to an impulse (either pull down to mass or pull up from mass) there's gotta be a constant power draw - however small (my Shelly plug measures it as non-zero <0.1~0.5W) - to the logic board to compare it against.

(warning: back of the envelope calculation)

At scale on a house one would have a bunch of such soft button devices†, cumulatively it might be on the 1~5W scale. Across a 1M city it's going to be 1~5MW.

It's made worse by these devices having cheap transformers or switched mode power supplies whose non-linearity drive the power factor down to 0.5~0.7, which means it's pumping real energy production to 2~8MVA (plus on the utility side electrical hardware needs to be scaled up because e.g loss doubles)

Which means for my town we're basically throwing 50~200MVAh a day right down the drain - or rather either burned up in the air or buried down "places that are not of honour" - because it doesn't make sense to have power factor correction economically (either on the device maker side, which would rise the BOM a few cents up, on the residential side where the cost is prohibitive, or on the individual size where people prefer buying cheap, electrically terrible, knockoff devices). Because yeah, in the EU passive PFC - which raises PF ~0.5 to ~0.85 - is mandated above >75W only.

Comparatively to the overall energy production and usage it's small, but in absolute terms it boggles the mind that as a society we're able to handwave such amounts of energy.

† I'm not counting stuff like powerbanks or chargers but again back of the envelope it should overall fold into the range, making the worst case conservative.

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