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Audacious Plan to Make Electricity as Easy as WiFi

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Re: Audacious Plan to Make Electricity as Easy as WiFi

#61

Post by snarfy »

scottlocklin wrote: post #27
domdip wrote: post #17

Earlier quoted context omitted.

Well, in principle you can divide one transmitter's attention to several devices over time. (Either by changing the direction of the antenna, or more sophisticatedly via beamforming.) Otherwise I agree with you. Even the tone of this article is unconvincing. I wonder what Andreessen’s due diligence team was thinking, maybe the patents have value?

If I were a VC invested in this, I'd want hearing tests on the engineers working on this project; once a month, over time. Of course, if I were a VC, I wouldn't invest in this, because it is physically retarded on inspection. Whoever did the dil on this is either a fool who doesn't understand basic physics, or was bribed somehow. Off the top of my head a) sound energy falls off as 1/r^2, b) that those sorts of energy…

With electromagnetism the energy fall off depends on the radius and the wavelength. If the wavelength is is greater than a certain amount of the radius (the Fraunhofer distance) then the energy fall off is a linear 1/r. This is called the near field.

http://en.wikipedia.org/wiki/Near_and_far_field

Re: Audacious Plan to Make Electricity as Easy as WiFi

#62

Post by s_q_b »

gerbal wrote: post #54
s_q_b wrote: post #51

Earlier quoted context omitted.

She's not defying the laws of physics. It's a tracked directional system that concentrates the ultrasound at the point of the device. Honestly, not even really that out there as far as the physics is concerned. EDIT: Unlikely. Children hear better in upper ranges, not lower. And animals are unlikely to be too perturbed. These types of noises are generated naturally all the time. The challenge here is the engineering.…

The patent application[1] lists the transmission frequency as 40-60kHz, a high frequency. Humans typically hear up to around 20kHz, dogs 44kHz, cats 79kHz. Not Low frequencies. A directed, concentrated, high decibel volume, in the 40-60kHz range is not the sort of thing found naturally 'all of the time.' As other posters have mentioned, transmitting energy via sound is likely impossible do both safely and at useful a…

Initial patents rarely resemble final technology. There's something you get out right away. Most startups do this.

Re: Audacious Plan to Make Electricity as Easy as WiFi

#63

Post by vkuruthers »

I can't see how this would be efficient enough to charge a phone. Does anyone have a rough idea of what the end to end efficiency of this system would be?

Also if it's a beamed technology, does it then need N transmitters to charge N devices? How is the beam targeted?

Seems like a simple inductive charger would be much more practical.

Re: Audacious Plan to Make Electricity as Easy as WiFi

#64

Post by gerbal »

s_q_b wrote: post #62
gerbal wrote: post #54

Earlier quoted context omitted.

The patent application[1] lists the transmission frequency as 40-60kHz, a high frequency. Humans typically hear up to around 20kHz, dogs 44kHz, cats 79kHz. Not Low frequencies. A directed, concentrated, high decibel volume, in the 40-60kHz range is not the sort of thing found naturally 'all of the time.' As other posters have mentioned, transmitting energy via sound is likely impossible do both safely and at useful a…

Initial patents rarely resemble final technology. There's something you get out right away. Most startups do this.

Given that the patent followed a prototype, it has to in some way resemble the final tech.

The fact remains that Ultrasound is not an efficient mode of energy transmission [1]. Wireless induction is almost certainly more efficient over the same distances. And ultrasound is a potential nuisance and hazard to wildlife and pets in way EM broadcasts simply aren't.

[1] http://dx.doi.org/10.1109/IECON.2011.6119486

Re: Audacious Plan to Make Electricity as Easy as WiFi

#66

Post by hsshah »

I cannot judge the merit of this approach but I have been eagerly waiting for WiTricity or Cota to show up in my electronics gadgets. Can't wait to get rid of charging cables. I am sure the engineering takes lots of effort and time but I remember seeing WiTricity TED talk years back :(

I was expecting Apple to integrate such technology for it's Watch. I don't want one more device that I have to remember to charge everyday.

http://witricity.com http://techcrunch.com/2013/09/09/cota-by-ossia-wireless-powe...

Re: Audacious Plan to Make Electricity as Easy as WiFi

#67

Post by malandrew »

wmeredith wrote: post #49
malandrew wrote: post #18

I was really hoping there was more hear about the technology, specifically what they are doing differently and the backgrounds of the engineers making this a reality. The process of raising money and getting buy-in is far less interesting than demos showing how much electricity is going into the transmitter and how much is being received by the receivers, especially under the conditions he says they can deal with (mo…

It's a very strong sell from someone who just cut them a check for $10 million .

Exactly. They just raised $10 million. Why do they need any selling at all? Obviously they should be back at work building their product and figuring out the manufacturing logistics for when it's ready. Hyping a company right after raising a round and way before they have a product is strange.

Re: Audacious Plan to Make Electricity as Easy as WiFi

#68

Post by s_q_b »

kybernetyk wrote: post #56
s_q_b wrote: post #47

Earlier quoted context omitted.

Meredith Perry is no fraud. She was in a Penn graduate program before this venture, and has worked at NASA. It's directional transmission technology. The power loss is minimized as the ultrasound is directed and focused at a particular location. There's no inverse square law here, and it's easily within the bound of known physics. As far as I know, (indirect relationship with the a good friend of the founder, that I…

> This is a "First they dismiss you. Then they laugh at you. Then you win" scenario. Then god knocks at your door and angrily asks why you didn't obey the laws of physics.

Tell me what part of the physics you find impossible.

Re: Audacious Plan to Make Electricity as Easy as WiFi

#69

Post by jerf »

scottlocklin wrote: post #60
jerf wrote: post #46

Earlier quoted context omitted.

"a) sound energy falls off as 1/r^2" No, it doesn't. That's how it falls off when being transmitted perfectly spherically in an environment that won't reflect or refract anything. Consequently, this turns out to be a not-very-useful equation in practice. In particular ultrasound can be beamed just like light, making the "perfectly spherical transmission" not even a close approximation, just as it is not a good approx…

"In particular ultrasound can be beamed just like light, making the "perfectly spherical transmission" not even a close approximation" You do realize that energy from a point source of light also falls off like 1/r^2, right?

OK, since conversation has moved on, let me be blunt: You don't know what you're talking about. Your physics 101 education is not the end-all, be-all of physics, and what "point" transmission does doesn't matter because we aren't talking about points. You are in no position to be lecturing people about physics; you are in a position to be lectured to about physics.

Re: Audacious Plan to Make Electricity as Easy as WiFi

#70

Post by jacquesm »

malandrew wrote: post #23

Here's a supposed demo of the device in action: http://on.aol.com/video/ubeam-wireless-power-demonstration-a... Only thing is that I want to see what's in the box on the left. There's nothing to show that the transmitters are actually transferring power and aren't simply telling the other side to turn on and change resistivity to a hidden battery on the left hand side (or even draw from the battery in the iPhone conn…

Current or voltage is not relevant you want current and voltage. Just voltage without Ri doesn't mean anything, you could easily get any kind of voltage by using a simple transformer. That doesn't mean useful power is transferred for that you need to apply a load and measure current through the load and voltage across the load.

Also, AC voltage on an analogue meter is usually calibrated at 50 or 60 Hz, not at much higher frequencies.

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