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.
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.
“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.)
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.
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)
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.
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”
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.
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.
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 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.
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.”
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”
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
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-month
Those 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
