The uBeam FAQ

[Fungus]

I can't see how they could have used this open frame and clearly mains input PSU as a demo on a trade show though, even the most incompetent engineer would not put that kit together for a demo.

Good point. Why wouldn't they use a metal-caged PSU instead of one that could kill gerfingerpoken visitors.

[EEVblog]

https://webcache.googleusercontent.com/search?q=cache:4arGdU-Y_7YJ:https://oshpark.com/profiles/ubeam 

LOL
Order your own board now!
https://oshpark.com/profiles/ubeam

Well that didn't take long, uBeam have removed the shared project. It was there when I posted the link. You can still use the archive link above.

[EEVblog]

I can't see how they could have used this open frame and clearly mains input PSU as a demo on a trade show though, even the most incompetent engineer would not put that kit together for a demo.

Good point. Why wouldn't they use a metal-caged PSU instead of one that could kill gerfingerpoken visitors.

It looks "electronicy" for the muggle investors?

[EEVblog]

These claims in Oct 2017 turned out to be laughable, and even internally inconsistent.
You can't have "meters" (plural) range at max power, and also have max power at "0.6-1W @1m"

And you can't really charge a phone in any meaningful way with 0.6W-1W. Even a lousy standard USB port is 2.5W (5V x 0.5A), so uBeam could be almost 5 times worse than an already slow standard USB port.
And this is their own MAX claims!
No wonder they put their tail between their legs and pivoted to low power IoT, Meredith Perry's dream of charging a phone with Ultrasound failed miserably as everyone predicted. Once she was booted and the adult supervision came in the claims of charging a phone quickly faded into the ether.

[EEVblog]

I've been informed that they also had the big transmitter arrays boxes there (with he usual COTS transducers), so all that stuff in the photo is likely receiver stuff.
Still makes the 50-100W SMPS puzzling.

[mikeselectricstuff]

So what is this "Burst circuit"?
Clearly they got another board made as the photo shows a 2nd board attached to the Burst circuit, and the silkscreen is different on the OHSpark one vs the photo unit.
A guess would be that the "burst circuit" perhaps decodes any data modulation on the ultrasonic, and the board next to it is the energy harvesting circuit?

Or maybe stores up energy in a big cap to deliver in bursts to provide a reasonable charge current for a battery.

[sdpkom]

There are clearly two antennas on the FPGA board.
I wonder how this no electromagnetic thing going with two rf antennas and an open switching ps

[StillTrying]

"I wonder how this no electromagnetic thing going with two rf antennas and an open switching ps"

There will be quite a bit of high power ~40kHz nearby switching going on as well.

The demo kit doesn't look realistic with no wires anywhere, perhaps it's just for show, with 30 engineers X 18 months surely they could have put it in an aluminium case, instead of a pizza box so that it at least looked right.

With the size of the receiving panels, surely just sticking a much smaller PV on the the IoTs would be better and wouldn't need any of the transmitter junk.

I wonder how they're getting on with all these 2017 Q4 claims, they must have well known what they were actually capable of at the time. If I was an investor I would be using some F words, and they wouldn't be funny or more funding.

[sdpkom]

With the size of the receiving panels, surely just sticking a much smaller PV on the the IoTs would be better and wouldn't need any of the transmitter junk.

A PV indoors generates 10s of microwatts.
You need to aim a high power light source at it to power it.

While outside you get 1000W/m^2 insude you get 0.5W/m^2

[coppice]

With the size of the receiving panels, surely just sticking a much smaller PV on the the IoTs would be better and wouldn't need any of the transmitter junk.

A PV indoors generates 10s of microwatts.
You need to aim a high power light source at it to power it.

While outside you get 1000W/m^2 insude you get 0.5W/m^2

Most IoT devices with PV would generate no power at all, as they are located in dark corners and cupboards.

[glarsson]

Most IoT devices with PV would generate no power at all, as they are located in dark corners and cupboards.

It's cheaper to install a light bulb than an ultrasonic transmitter in the cupboard.

[sdpkom]

Most IoT devices with PV would generate no power at all, as they are located in dark corners and cupboards.

It's cheaper to install a light bulb than an ultrasonic transmitter in the cupboard.

And if you already got power inside the cupboard, why not just plug it in?

[glarsson]

And if you already got power inside the cupboard, why not just plug it in?

Then it's not wireless and you can no longer get investor money to sustain your business.

[PaulReynolds]

Macvoices video of uBeam floor demo at CES



So they power an LED at an unclear distance, maybe 1 meter, it's that white box from the top right of the recent image from the demo kit. Watts, dB, or any other performance metric not given. The transmitter looks to be (from the video in the background) the white plastic box shown about a year ago, labelled March 2018 in the attached image. That seemed to have 16 by 16 Murata profile devices, so 256 total and around 7.5W absolute max acoustic power out if they stick to 145 dB (.0256m^2 and 290W/m^2), likely less. There is a noticeable delay in tracking finding the new position - where's the beam going in that time?

Claims of safety made me choke. Yes, ultrasound bounces off skin (99.9%), but hair causes heating, and at 145dB and up there are papers showing measurable temperature rises, and ultimately death, in mice and rabbits. Also claim lots of "3rd party testing" shows it's safe - if so they should release it. Also claim safety as it's a controlled beam, if they are using Murata sized devices there are grating lobes sending out additional beams at 45 degrees. No mention of OSHA, UL, FDA, or other regulatory bodies.

http://archiwum.ciop.pl/59815

"According to Allen, Rudnik and Frings, a mouse dies from overheating after 10 s to 3 min of exposure to a signal of 20 kHz and level of 160 dB [10]. According to Danner, a lethal level for signals of 18–20 kHz for an unshaven mouse were 144 dB and for a shaven mouse 155 dB [21]. Acton obtained similar results and extended studies to larger animals such as guinea pigs and rabbits [22]. "

They say they are focusing on "Industrial IoT", low power sensors etc. More robust demo in private at the suite where they power cameras and sensors. Why admit your floor demo is "not robust"?

[mikeselectricstuff]

"I wouldn't be doing my job if I didn't ask about safety"
..and power transferred, cost, efficiency... ?
Thought not. Typical clueless idiot journalism

[Fungus]

"I wouldn't be doing my job if I didn't ask about safety"
..and power transferred, cost, efficiency... ?
Thought not. Typical clueless idiot journalism

Apparently you can replace the 9V battery in your smoke alarm with one of these.

That's progress!

[djos]

"I wouldn't be doing my job if I didn't ask about safety"
..and power transferred, cost, efficiency... ?
Thought not. Typical clueless idiot journalism

Apparently you can replace the 9V battery in your smoke alarm with one of these.

That's progress!

so if your house catches fire during a power outage, you are royally fk'd! 

[PaulReynolds]

I expanded that post to a blog, for those interested:

https://liesandstartuppr.blogspot.com/2019/01/more-ubeam-at-ces-2019-macworld.html

[Daixiwen]

I didn't notice in the partners table before, their partnership with Korean CE Co. for a "wirelessly powered robotic vacuum". With the amount of energy required, you'll probably get your house cleaned with the ultrasounds alone

[StillTrying]

I expanded that post to a blog, for those interested:
https://liesandstartuppr.blogspot.com/2019/01/more-ubeam-at-ces-2019-macworld.html

 
I watched the blue-white RX LEDs coming on 2 or 3 times in the video, with superbright LEDs that amount of light could be as low as 25-30mW.

In this thread somewhere Howardlong and me have both tried to create subharmonics in the air by mixing 2 40kHzs 1 or 2kHz apart, and neither of us could hear anything for some reason, I checked with a very close EMC that they were mixing, there seems to be more to it than just 2 cleanly mixed 40kHzs.

So what is this "Burst circuit"?

I dunno, a guess is it's something to do with powering 4 receivers at the same time.

[PaulReynolds]

I expanded that post to a blog, for those interested:
https://liesandstartuppr.blogspot.com/2019/01/more-ubeam-at-ces-2019-macworld.html

 
I watched the blue-white RX LEDs coming on 2 or 3 times in the video, with superbright LEDs that amount of light could be as low as 25-30mW.

In this thread somewhere Howardlong and me have both tried to create subharmonics in the air by mixing 2 40kHzs 1 or 2kHz apart, and neither of us could hear anything for some reason, I checked with a very close EMC that they were mixing, there seems to be more to it than just 2 cleanly mixed 40kHzs.

I was being very generous to uBeam with a 100mW estimate in the post, trying to be as "best case" as I can. It most likely is closer to what you are suggesting at 25mW.

Subharmonics are different than nonlinear sound generation. Subharmonics are when there's a nonlinearity in the system and the system itself generates a lower frequency from a single frequency source and creates an integer division of the fundamental frequency. The eardrum is a good example of this, at round about 110 to 120 dB the ear stops responding linearly (specifically, the restoring force on the eardrum goes asymmetric), and the first subharmonic starts appearing at 30 to 40dB lower (1/2 freq), and then at 130 to 140 dB the second subharmonic (1/4 freq)starts appearing around 60-70dB lower (from memory, need to reread the papers to confirm). There are a few studies covering this, so the dataset is fairly limited - it's utterly unethical to perform such experiments on people for a start, and it's a tricky setup to get right.

Paper on subharmonics in the ear
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3387311/

Parametric sound is where the inherent nonlinearity of the air is used to generate sound at a location, and uses high frequency sound to ensure the array is larger than the wavelength so steering and directionality is straightforward. It needs to be 110dB+ for that to happen IIRC in theory, 130dB+ in practice, but you lose at least 60dB in what you hear, so I doubt with a regular source you would have much luck. In theory you can generate any frequency you want, not just an integer division of the fundamental.

https://en.wikipedia.org/wiki/Sound_from_ultrasound
https://www.holosonics.com/fundamental-limitations-of-loudspeaker-directivity

BTW in looking up a link on nonlinear sound I found this Kickstarter backed project that resulted in a 98 element array transmitter using Murata style devices that probably puts out a similar amount of power to the uBeam transmitter. For $250 $500 inc amp.

https://www.soundlazer.com/shop/

[sdpkom]

So what is this "Burst circuit"?

I dunno, a guess is it's something to do with powering 4 receivers at the same time.

Maybe it's better to start with powering just one receiver, for part of the time, ehh....?

[EEVblog]

Macvoices video of uBeam floor demo at CES

So they had a "public" stand with a demo but it's not their "real" latest demo which you have to be invited to their private suite to see?
What company does this if they don't have something to hide? CES is where you show off your latest stuff and wow the media.
Of course, we know the answer 

[EEVblog]

Whatever happened to these transducers?

[Fungus]

"I wouldn't be doing my job if I didn't ask about safety"
..and power transferred, cost, efficiency... ?
Thought not. Typical clueless idiot journalism

You'd think there'd be one journalist at that show with camera and a clue, but nooooo.