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The uBeam FAQ
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EEVblog:

--- Quote from: Fungus on June 25, 2019, 04:20:17 am ---
--- Quote from: EEVblog on June 25, 2019, 03:54:29 am ---No one wants to charge their phone @ 1W at a distance of 20cm, and at horrible efficiency.

--- End quote ---
...using a charger that makes your phone the size of a brick, needs to be held in the air and aligned, and costs hundreds of $$$.

--- End quote ---

It's not nearly that bad, you can lie it face down unusable on the table and have the TX above, really practical.
Oh, oops, it sucks at 2m, forget I mentioned it...  ;D
PaulReynolds:

--- Quote from: EEVblog on June 25, 2019, 03:54:29 am ---And there you have it, as we all knew uBeam is a flop for charging your phone. THE thing that Perry said was doable from the start.
No one wants to charge their phone @ 1W at a distance of 20cm, and at horrible efficiency.
Or 0.35W at 2m, at even worse efficiency  :-DD
I love how they used the elipse bubble to inflate the figures, just draw a straight line from each tip and that's your data, probably best case.
No wonder they had to pivot to low power IoT.

--- End quote ---

The numbers here are weird. I updated the blog post to cover this but with a large area transmitter you can maintain maximum pressure (say 145 dB) at the receiver as it moves out by just using more transmit area to compensate for the air losses, with subsequent efficiency loss. That would make the line go straight for a distance before dipping. Also note these numbers imply 30% receive efficiency which I don't believe, and would have implied 60% receive efficiency on the next gen devices which I really don't believe.

And if that beamplot is genuinely focused at 2m (cough 1.2m cough) those transducers either only send sound forward (implying not much use for steering in a phased array), or they found a way to defeat physics and prevent grating lobes in phased arrays with non-ideal pitch. The latter is worth billions so I don't think it's that.

In 2013 getting your phone charging at 1W at 1m was respectable. Today... no.
sdpkom:

--- Quote from: PaulReynolds on June 25, 2019, 05:41:25 am ---
In 2013 getting your phone charging at 1W at 1m was respectable. Today... no.

--- End quote ---

iPhone X (and most phones today) use a 10Wh battery, which is good (in my experience) for 7AM->9PM so ... ~14-15 hours.
Average power consumption is therefore ~700mW.
800mW would charge your phone (reeeeeaaaaaalllllllly ssssssssssssssslllllllllllllllllllllllllllllllllooooooooooooooooooooowwwwwwwwwwwwww!).

But if you did have 24/7 wireless power, 1W is all you will need to keep your battery full.

Now, if you have line of sight, range, and orientation issues, you obviously need more. If you can only charge 50% of the time you need 1.5-2W. If you can only charge 10% of the time.... you need 7-10W.

_______________________

From the demo they gave at the ourcrowd summit it was clear that
The large unit (the one on the top of their twitter account) has some tracking and phased array capabilities

The small unit (the one they advertise as beta kits), is a good old plane speaker, directing high volume ultrasound forward, no tracking or even detection of receivers.

I think the name "the twitter unit" is suitable for both systems ;-)

https://www.youtube.com/watch?v=azBzKWqUoXU&feature=youtu.be
@ 22:50 you can see the beam is fixed, and the detector is inserted into the beam.... if there was tracking (or safety), it would only appear on the center of the plate.
[this is the "beta" unit]

@25:30 you can see how it would look if it was tracking the receiver.
[this is the old unit with the camera- let's call it the twitter demo
PaulReynolds:

--- Quote from: sdpkom on June 25, 2019, 06:02:21 am ---
--- Quote from: PaulReynolds on June 25, 2019, 05:41:25 am ---
In 2013 getting your phone charging at 1W at 1m was respectable. Today... no.

--- End quote ---

iPhone X (and most phones today) use a 10Wh battery, which is good (in my experience) for 7AM->9PM so ... ~14-15 hours.
Average power consumption is therefore ~700mW.
800mW would charge your phone (reeeeeaaaaaalllllllly ssssssssssssssslllllllllllllllllllllllllllllllllooooooooooooooooooooowwwwwwwwwwwwww!).

But if you did have 24/7 wireless power, 1W is all you will need to keep your battery full.

Now, if you have line of sight, range, and orientation issues, you obviously need more. If you can only charge 50% of the time you need 1.5-2W. If you can only charge 10% of the time.... you need 7-10W.


--- End quote ---

In the 2012/13 era the iPhone 5 was the latest and it had a ~5Wh battery, so a factor of 2 there, USB had lower max rates, and battery management didn't allow for 'rapid charge' for some of the recharge cycle.

Technical people careful of such things may have tended to use "trickle charge", "top up", "maintenance" with regard to charge rate, and "ubiquitous" with regard to availability, when discussing business models with potential funders at that time, as the most common uses of such technology.


--- Quote from: sdpkom on June 25, 2019, 06:02:21 am ---From the demo they gave at the ourcrowd summit it was clear that
The large unit (the one on the top of their twitter account) has some tracking and phased array capabilities

The small unit (the one they advertise as beta kits), is a good old plane speaker, directing high volume ultrasound forward, no tracking or even detection of receivers.


--- End quote ---

I expect the smaller one is the one for the beam plot, and so would want to see the beam plot with the larger steered beam. I'm confident it would not be pretty.

And all that money on transducers to never steer? It's pointless without that. Just get a large plate and drive the hell out of it with stacks from behind and be done, most of the development time of that would be waiting for the component shipment.
Fungus:
Even with "next gen" technology:

At 2-m maximum useful range you'll need a charger every ten or fifteen feet along the warehouse for this to be useful.

This? Not gonna happen.


It also only charges one thing at a time so I wonder if they've added any sort of prioritizing mechanism to make sure the lowest battery people get the charge in meetings, not the people who don't really need it.



If not? I see people waving their phones in the air to try and get charge, maybe even fist-fights breaking out.  :popcorn:

("Excuse me, I'm a bit low, could you put your phone under a piece of paper so I can get some charge?")
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