Slashdot Mirror
CleanSpace CO Sensor Runs On Freevolt RF Harvesting
mspohr writes: A few years ago, a Kickstarter was set up to develop a locator tag powered by free radio frequency (RF) energy harvested from the environment. This was called a scam here on Slashdot and was shut down before it was funded on Kickstarter. However, it now appears that the concept is not as far-fetched as some predicted. A UK company CleanSpace has developed a carbon monoxide (CO) sensor which is powered by free RF. A review of the product has been posted on YouTube. It uses Freevolt technology to keep a battery charged and the CO sensor running. Since they have several thousand of these devices collecting data, they do appear to work and it seems to be in the 'not a scam' department.
...cold fusion.
You can run a CO detector on it. You might be able to run a smoke detector on it, although you'd think they'd be doing that if they could. Perhaps you could run a wireless keyboard or mouse over a very short range. Harvesting radio noise isn't a new idea.
It's not a general battery replacement. Their website says "RF Energy Harvesting For the Low Energy Internet of Things" which is a fairly ugh slogan, but it seems relatively accurate. I don't see any reason why you couldn't fire up a microcontroller, do a little bit of sampling, and report your results before going back to sleep until the next time your capacitor was full.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
However, the amount of power is available is very small, and is not suitable to power wifi or bluetooth devices - even BLE. This does not mean in principle you can't use it for things that use orders of magnitude less power.
we need to know
Old concept, but using the AM band RF was probably easier in the 60s than today.
Stolen? No. Settled law.
Back in the 80s a new 100kw FM transmitter was setup in Colorado right next to an EEs house. He couldn't get away from the noise, on the land line, TV etc etc.
He set up a 'faraday wall' (between 99 ft antenna towers) and inverter, harvested about 20% of the stations output, and sold it back to the power company. The FM station sued, they lost.
In the end they worked out an agreement, IIRC the EE got something like 2 or 3 times fair market value to go away.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
1. "iFind tag powers itself."
No, no it does not.
2. "Your very own portable air pollution sensor."
At best it's a CO detector.
3. "For the low energy Internet of Things."
If you think there's even a TCP/IP stack on these things, let alone a Wifi radio, you're high.
Crystal radios have existed for over a century. They certainly work using transmitted RF energy alone. What they don't do is all the complex whizz-bang shit that's being claimed in the marketing spiel, that makes them sound OMGWOW instead of ohthatagain.
In other news, I bought a pair of shoes and I started beeping when I exited the store a couple of days ago. INTERNET OF THINGS, MAN.
Sounds dubious. FM band wavelengths are pretty short, so the tall towers are to get you line of sight, not for antenna gain. 20% is very good efficiency, so he had to be doing near field coupling right next to the radiator (on the order of feet) or else a HUGE array surrounding the tower.
Sorry France, but both you and we (US) are letting these beasts in.
an ill wind that blows no good
From the scam article: " this one claims it doesn't require any batteries
From the current article: " It uses Freevolt technology to keep a battery charged
Can anyone spot the difference?
I'm an American. I love this country and the freedoms that we used to have.
And easier and more popular in the 20's and 30's. Any kid knew how to build an 'RF harvesting device'. The technology was lost to most.
It may be that it was blocking 20% of the radiation pattern but harvesting efficiency could have been much less.
Localizers here we come! Vernor Vinge would be proud!
http://blog.regehr.org/archives/255
https://en.wikipedia.org/wiki/A_Deepness_in_the_Sky#Localizers
As a potential lottery winner, I totally support tax cuts for the wealthy
Oh come on. I've seen the "I can run my on harvested RF energy!" scams come and go on Slashdot. Yes, they get shot down, but not for being *technically* impossible, but being *practically* impossible.
Yea, you can transfer energy using RF from one point to another without wires, but the problem here is it's pretty inefficient to do this because the amount of power falls by at least the square of the distance. So what may work at 1' fairly well using 10 watts of input RF power, is going to require something like 100 watts when you double the distance and 1,000 when you double it again (4'). (Please feel free to correct my math, but you get the idea).
So, yes, if you have a "low power" device, something that doesn't consume much power on average, you can likely scavenge enough power from the RF around you in most places to keep running. HOWEVER, most of the scam devices are for applications that REQUIRE always on radios and significant computational power. These devices consume too much power to be practically powered by foraging RF energy, especially in the home or office where the largest amount of RF power is likely coming from your Part 15 regulated WiFi devices which are limited to about half a watt and can be tens of feet away.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
I've worked on this project and it doesn't work.
Basically all it is is an antenna with a half bridge diode rectifier. This is pretty straightforward however the problem is that despite using 'zero drop' diodes the ambient RF energy does not produce a sufficient voltage (power out of the antenna with the line impedance at the diode) to switch the diode properly which causes a rapid drop off in efficiency. Basically the diode is still in the sloped part of the IV curve (zoom in on an IV curve at the knee). This combined with the fairly low amounts of power available means that the power output of these things is in the 10s of uW, which is less power than is consumed by the charge pump needed to top the battery up! So how does it work then? Check the tear down photos and you'll see a massive battery...
The other interesting thing about this 'technology' is that you can calculate the energy density of a harvester, it's simply the mean time till failure x power output / volume of device. When you do this calculation you quickly realise that due to the size of the antenna needed to see any appreciable power the device would have to last for 10-20 years to begin to approach the energy density of even coin cells (including the casing)!
The fact this works doesn't make the other any less a scam. The prior project still doesn't work and the analysis is still valid. Unless there is a design using freevolt to make the other a reality it's completely irrelevant.
Even with the dubious 20% efficiency claim, he'd be getting 20kW. At today's ~12 cents per kWh in the U.S., he'd be selling it at ~$85 a month. Seems hardly worth the hassle.
don't forget all the people killed to loot resources to keep the secular western elites wealthy and happy and all the western non elite dependent on their welfare states.
it just payback.
One of the side-effects of this device, implicit in its design, is that it will re-radiate mixing products of all received signals. This tends to interfere with nearby radio reception.
Bruce Perens.
You don't sell it to make money, you sell it to piss them off.
Stolen power? We called them crystal set radios when I built them when I was a kid.
It has A BATTERY in it. Even if it collected ZERO free RF energy, it would still run for quite some time. Consequently, it DOES NOT FOLLOW to assert that it must be functional because there are several thousand in operation.
>> You can run a CO detector on it
Better not run CO or smoke detectors.
If you wifi fades, or your detector is in a blind spot of your wifi (and these can move over time), then you will potentially die.
Don't do that. it'S dangerous.
Also. Its still BS to call that "free" energy. There's no such thing.
aaaaaaa
No, 20kw running 24 hours a day all month is more like $1600 in electricity.
Yes, this is correct.
The diodes are operating in their Square Law region, which means that as an RF Detector it must be woefully inefficient.
Knowledge which should be routine for any RF engineer, or for any kid who has built a Crystal Set.
I built an AM radio – with no battery – that would audibly play local stations. This was in the 1970s.
Surely many slashdotters did the same. Heath-Kit.
I prefer to be certain when stopping the bad guys, and nuke from orbit.
--sf
machine that harvests energy out of thin air and device that detects odorless and colorless gas.
Ah, yes, It's photoshopped... (after xkcd)
About $1750 a month, not $85.
https://www.google.co.uk/search?q=20+kW+x+1+month+x+(12+cents+per+kWh)+in+USD
This trend has been ongoing for decades. People with no STEM aptitude that are heavily enthused by "science" (or rather their pop-culture knowledge of science) with loud obnoxious voices declaring science is known, that the limits are what they have been fed through limited education and with a degree of arrogance combined with zealotry unseen since the dark ages.
This is exactly why pop-science shouldn't be a thing - the idiots of the world are better off raving about petty divisive non-issues like those in the social realm than they are ranting about Jobs, Musk or other techno-cult leaders.
The end result here is that the actual inventor of a technology failed to see the profits of that technology, almost certainly reducing his chances of developing further technologies and propelling the species further. Instead we have a company run by people with connections in marketing, sales and business driving the technology pretty much guaranteeing to corrupt it.
A technology from the days of Tesla, rediscovered by a modern genius and usurped by weasels thanks to "science" zealots. What's next? The EM Drive, Woodward Effect devices, LENR?
A note for the zealots, so you know who you are even if you fight it: the above 3 technologies have been proven by multiple parties, decried by zealots are in the process of review by authoritarian labs you will one day hail as miracle workers.
Umm, 20 kW * 24 hours/day * ~30.4 days/month = 14,592 kWh/month; @ $0.12//kWh = $1,751.04/month.
Nuff said.
> Stolen? No. Settled law.
That story has all the makings of an urban myth.
I went looking for confirmation and all I could find was this substantially different telling.
#18 08 June 2007, 03:34 AM
bugeye
I know an electrical engineer who had a problem with a local television station. They erected one of their transmitter antennas very close to his property. He was unable to watch any television channels because of its power and proximity. It was also causing electrical problems with some appliances and other kinds of interference.
He complained to the station and they claimed that it was not their antenna causing the problem. So, he set up a "christmas tree" in his backyard with an induction coil and 100 watt bulbs. It lit up nicely, and within a couple of days, the television station employees came to apologise and set up some kind of shielding for him.
If you have a source, I'm sure I'm not the only one here who would like to read it.
I've heard this story many times. Sometimes the station is AM sometimes FM
I actually want to believe at least one version of it is true.
Does anybody have a reasonably legitimate link to background on this story?
Oh come on, there is metal in the environment. Every metal object will cause IMPs. Idiot, go back in your box.
Looks like AmiMoJo forgot her password.
Confucius say, "Find worm in apple - bad. Find half a worm - worse."
Isn't that how demolition derbies work?
APK likes to ask for responses to the same things over and over. Maybe he just likes the responses?