- cross-posted to:
- hackernews@derp.foo
- cross-posted to:
- hackernews@derp.foo
Researcher has developed, at a cost of less than one dollar, a wireless light switch that runs without batteries, can be installed anywhere on a wall and could reduce the cost of wiring a house by …::A U of A engineering researcher has developed a wireless light switch that could reduce the cost of wiring a house by as much as 50 per cent.
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No explanation of how it works, but I’m guessing it slides an RFID chip in or out of a Faraday cage.
It sort of explains it, if you already know how RF charging works. It’s still pretty new tech, but has been around for a bit.
“RF wireless charging is a type of uncoupled wireless charging in which an antenna embedded in an electronic device can pick up low level radio frequency waves from external sources and convert the waves’ energy to direct current (DC) voltage.”
So knowing that and the article referencing about wireless light switches already being a thing, but being battery powered, it seems that it’s a standard wireless light switch that has just been modified with an rf wireless charging receiver that will charge a small battery or some capacitors to run the light switch.
IMO, until you’re using rf to power more than just light switches, you’re wasting a lot more electricity than it’s worth, compared to changing out batteries in your light switches once every like 5 years. If RF gets standardized completely and it starts helping to power a whole mess of things like your smart watches, phones, air tags, clocks, etc then it will be pretty sweet.
Didn’t the soviet union have radio bugs that worked like that? No power of their own and hard to detect but if you blast them with RF they can use some of that energy to turn into small very weak signal transmitters. One of the culprits of ‘Havana sickness’ if I remember.
Found the sauce
https://en.m.wikipedia.org/wiki/The_Thing_(listening_device)
“RF wireless charging is a type of uncoupled wireless charging in which an antenna embedded in an electronic device can pick up low level radio frequency waves from external sources and convert the waves’ energy to direct current (DC) voltage.”
I can’t find that quote in the article—or anything that definitively indicates they’re talking about RF power rather than RFID signals (other than saying the transmitters “power up” all the switches, which could just be sloppy terminology.)
Sorry. Yeah, that’s not a quote from the article. Just just something I went and grabbed elsewhere real quick to explain rf power.
The article says they are powering it using dedicated transmitters:
“each floor would have one or two RF (radio frequency) power transmitters to power up all switches inside the house.”
It’s confusing because earlier they talk about energy harvesting, which implies “free”. But then they talk about how you will need to run these transmitters, which certainly isn’t free.
That’s probably an explanation from Wikipedia or sth
Isn’t this ambient RF that’s there anyway, like your WiFi network and stuff like that? I don’t see any harm in harnessing it for low power applications like those switches, sensors, etc.
No. They need a separate rf field generator. Not just picking up on any stray rf or rf from your wifi. It says as much in the article.
As to the technical reasons behind why your routers frequency can’t be used, I don’t know. I’m guessing the 2.4 and 5ghz range just isn’t something that works at a proper enough frequency to oscillate and gather charge. They’ve been using a lower frequency of around 915 mhz for rf chargers.
Enocean has been making battery free wireless light switches for almost 15 years. I’ve personally used them for about 8 years and love them. They’re a lot more expensive then the $1 quote in the article but still cheaper than an electrician. They work with a strike to a piezoelectric element to make energy and transmit the signal.
I use something like this for my wireless doorbell because people kept stealing the battery. I’ve had it for years and it works really well.
I know times are tough but who TF out here stealing batteries
It’s probably someone in his house. They either think the door bell is too loud or need the batteries for another device.
Ah yes those “other devices”… check the wife’s nightstand
I’ve worked with these professionally, but never actually found a way to purchase them myself. Can you recommend a supplier?
Various companies repackage or license the enOcean parts. I’ve used this one from Amazon for about 6 years and haven’t thought about it. I’ve also used others from this brand for 8+ years and had no issues. I bought an old house around Boston that had power in the ceilings but no switches anywhere so this worked perfectly for me and I was able to do it all myself.
Thank you!
Oh nice. My parent’s doorbell is a wireless one and I thought it was a trick. That they hid the battery and sold it with false advertising.
This article is scant on details. It harvests RF to power/charge low energy devices. What RF bands? Is putting these through a house knocking out bluetooth around it, or existing RF remotes for devices? Or is this some background RF that won’t penetrate deep into a house to begin with? There would be “1-2 RF transmitters” to power the whole house…that doesn’t seem great, that’s a ton of wasted energy emanating in a sphere from the transmitter to hit these devices all over. I’m not sure what problem this is solving, copper wiring cost of extended runs to switches? Isn’t this problem going to go away if some system like zigbee got standardized and the switch hardware was baked into the end device itself to be controlled by any of multiple control points?
I’d imagine it’s scant on details because it’s still a theory. The next phase of the competition is funds to build a proof of concept.
For sure, though I question the theory. Directional wireless power I think is feasible, but this sounds like blanketing (1-2 transmitters in a house with no regard for obstacles/direction, per the article). That sounds hugely wasteful, especially given how much more energy power takes vs. signal. I do think a zigbee type solution is the ultimate answer, because even if it goes back to batteries for wall stations, data transmission like that is so much less energy than power that the battery problem becomes null-ish.
Zero details bullshit article. How would it reduce the cost by 50% considering you’d need a smart relay board with connectivity and then wire all the light fixtures to them OR have separate wireless relay boards at every light fixture OR have smart bulbs and a gateway.
?
Wireless switches — consisting of a transmitter on the switch and a receiver near a light fixture or other appliance — have been around for many years, and have been proven that they can reduce the material and labour cost for wiring houses, says Kambiz Moez, director of electrical engineering in the Department of Electrical and Computer Engineering, but they require batteries to operate.
So the product already exists, what is novel here is a concept to harvest RF energy I stead of batteries.
I think this is the usual thing where some engineer/scientist has developed a product that’s interesting and put out a press release then a journalist got ahold of it, grossly misinterpreted what was being said and wrote an article speculating that this would lead to all kinds of things that are not even remotely possible.
The article claims this will somehow save money on wiring a house, but that emphatically does not seem to be the case, that’s not the problem being solved here. This isn’t a revolutionary breakthrough, this is just a slightly interesting design to power IoT devices via wireless power rather than the usual dime batteries.
I wouldn’t call it “harvesting” if you have operate power transmitters on each floor of the house. “Energy harvesting” usually means you are using something that is already present in the environment.
“each floor would have one or two RF (radio frequency) power transmitters to powe r up all switches inside the house.”
I imagine replacing the battery in your light switch in the dark (because you can’t turn the lights on) is probably rather annoying. This sounds like a cool idea.
Replacing the battery in your light switch is something you do maybe once every 3 years.
And you can still use your phone as a backup remote.
Seems like a solution to add light switches for people who have homes that weren’t wired properly with switches for their lights.
For those of us with proper wiring, this probably falls under “ain’t broke, don’t fix it”
Living in a 150 year old house without proper wiring, this would be an immense improvement.
Or folks like me who have an all cinderblock exterior.
Copper wires are expensive. And you need to house those wires in aluminum pipes. That’s a lot of metal that you no longer need to buy. Especially considering how many light switches in our homes.
And you need to house those wires in aluminum pipes.
The fuck are you talking about? Romex is just run in your walls. There’s no aluminum pipes in your wall.
Presumably they are in an area that requires armored cable, such as Chicago
Because of all the shootings?
Harvesting stray RF energy sounds like a cool technology for certain niche applications.
But for switching lights in particular, I much prefer smart bulbs vs installing stuff to put the switches in nicer places. It also makes it easy to dim a room or the entire house in the evening.
Wouldn’t it make more sense to make the light switch the smart part then you can have cheap bulbs. You want the technical bit to be the bit that doesn’t wear out and has to be replaced.
As someone who has smart bulbs and smart switches. The switches are a 1000x more preferable. It’s nice to be able to use my phone, but it fucking sucks needing to use my phone every time I want to control them.
Smart switches are one of the next things I’ll upgrade in the house. But some of my switches control fans as well, so there’s not a huge amount of choice when it comes to finding something that’s compatible and works with some sort of standard instead of having their own app.
That’s where occupancy sensors shine. I generally don’t have to touch my phone or switches.
Yeah, I agree. And then you can have your override immediately available and not be forced to use your phone all the time, or have to keep the switch on all the time.
If you have smart bulbs and want to turn them off temporarily, you have to do it through your phone or if you use the switch you need to remember to turn the switch back on or you can’t control the bulbs through your phone until you do. Makes so much more sense to have the controllers in the switches instead of the bulbs.
Plus less much heat to wear down the circuits.
For simple use cases, maybe. But if you want to use multi-colored bulbs or turn on only one bulb in a multi-bulb light fixture, you get that granular control with smart bulbs.
As for where I’d want to have the technical bits, what you said makes sense, but led bulbs are also supposed to last a long time. Maybe upgrading their technical bits every several years isn’t a bad thing.
The conclusion of the research is that solution energy efficient and cheaper. Smart bulbs are nice, but they solve neither of the issues mentioned. They need to be powered on all the time and you still need the switches either way, unless you design your home to be solely smartphone controlled but nobody does that.
What makes his system unique is that the switches run without batteries, harvesting energy from ambient sources such as radio frequency signals.
That is mind-blowing.
Last time i saw a product claiming to run on energy harvested from radio-waves, it was a kickstarter project that (surprise surprise) turned out to be a complete scam.
It is totally possible to harvest energy from radio waves, it’s just such a tiny amount that you could barely light a LED
Yeah that’s my point, the energy you can actually harvest is ridiculously small. Even if it was slowly charging a capacitor with this harvested power and saving it for later use, how often can i use the switch before depleting the energy faster than it charges? “oh sorry, you’ll have to wait 5min to turn on your lights again, It’s not quite charged enough”
My guess is you would get a couple seconds of light before needing several hours to charge it up again.
Not really. RFID operates the same way and has been around forever at this point. This whole thing is a gimmick, it doesn’t replace switches it just makes them more complicated and moves where they’re located. To switch mains current you’re going to need a relay which is more expensive than a simple switch and then you’re going to need to somehow tie a particular RF switch to the appropriate relay.
Sure you might be able to reduce the length of wire running through the walls a tiny bit, but that’s going to be offset by a significantly more expensive and complicated control circuit somewhere. The only way this makes financial sense is if the cost of copper gets so high that running an extra 50 feet of wire is more expensive than a series of microcontrollers and relays and the unreliability of using RF for control.
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I’ve heard of this before but I think it’s really a trickle charge. Not practical for charging a phone or anything like that.
I have a Philips Hue wireless switch that has no batteries. The click action when you press the button is enough to drive the transmitter. The button moves in about 4-5mm when pressed and that is all that’s needed to drive the transmitter.
What’s really mind-blowing is that such trivial amounts of energy runs a transmitter that sends a specially coded pulse (not even just an on off pulse of RF) thirty feet to the receiver.
I saw a similar device in a friends new build 3-4 years ago. It used the energy from you pressing the switch to transmit to the fitting.
Back in 1956, the Zenith TV remotes didn’t require a battery and just used the power generated by pushing the button. They were severely limited in the number of buttons available though, due to the technology of the time.
https://www.theverge.com/23810061/zenith-space-command-remote-control-button-of-the-monthThose worked by sound. No power was needed or generated by the remote.
From the article…
By pressing a button on the remote, you set off a spring-loaded hammer that strikes a solid aluminum rod in the device, which then rings out at an ultrasonic frequency.
I THINK I even remember, way back, random channel changes from tapping on a drinking glass or something similar… Cool tech for the time
My Xiaomi doorbell button works the same way.
Companies: That’ll be $49.99.
So, I’m not sure this is new. Unless this article is several years old.
These have been around for a fair few years, and it’s a pretty cool idea. Big Clive did a teardown video of a set 2.5 years ago.
So, unless this guy invented this thing considerably before that, I’m going to say it’s a tenuous claim at best.
My grandparents house has a chandelier controlled by something like this… The house is 24 years old now. This is nothing new at all.
You would still need to wire the house with power outlets for phones and lamps… Cutting down on the light switch wiring is interesting but not full on Tesla
This could be so easily abused…
Hey guys why do all my lights turn off and on when my neighbor uses a microwave?
