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| StillTrying:
I don't think uDream will be able to keep up with the number of companies desperate to incorporate this technology into their IoTs products. >:D |
| PaulReynolds:
--- Quote from: sdpkom on March 10, 2019, 09:22:51 am ---Some more info, They claim being able to transmit 1W at 1 meter, hunderds of mWs at 2m and 10s of mW at 5m, but when asking a bit more details, this was for an unspecified receiver size, unspecified transmitter model and unknown alignment. When they demo the system, they hold the receiver with fingers blocking parts of the beam, but not the white square. I assume this means it's at least safe enough so that it does not hurt. The receiver they demo is not delivering measurable power (2 wires you can connect to a meter, or some USB you can connect to a phone) instead it has an array of approximately 14x16 red LEDs which are not very bright to look at. When it's working, only about a 1/3 of the LEDs are lit. Assuming the LEDs are 5mW LEDs, this would be translated to about 350mW of usable power at short distance. The demo kit includes a slightly smaller receiver, approximately half the size. The kit includes the small transmitter, which does not lock on receivers but rather has a fixed focus and is always on. During conversation they said that All components of the kit are commercially available and ready to go to production. Its completely safe, when asking about Israel (demo was in Israel) they avoided the question. They said it's certified as safe by a 3rd party, they avoided answering who is the 3rd party. They avoided all questions about dBs in either side (transmitter or receiver). --- End quote --- Good info, reinforces everything from earlier. 1 Watt at 1 meter but still won't say how or demonstrate? Hmmmm. So when Techcrunch were told by uBeam in Nov 2015 that the system would do a minimum of 1.5W at 4 meters, and in many cases faster than a wire, were they 'mistaken'? https://techcrunch.com/2015/11/07/wireless-power-charger/ Ultrasound at 145 dB or less won't hurt fingers over a few seconds. Concern at skin is over time of long exposure and heat build up, especially in hair. Other concern is if it's on the ear, does it generate subharmonics and cause damage? Also any long term effects if exposed for hours a day, day after day. No info on dB levels is bullshit, that smacks of avoiding regulatory and safety standards, and I wonder if they even know what the limits are in Israel. Same with refusing to say who claimed it was safe - identity of the third party is critical to know validity. They need to look up the word 'certified' as well. I would be very surprised if that LED detector did not have batteries in the frame to amplify any received signals, I've thought that they were only using that to show the beam, not to actually claim it's self powered. Were they actually claiming that was all from energy harvesting, no batteries? |
| StillTrying:
--- Quote from: sdpkom on March 08, 2019, 05:48:29 pm ---The smaller transmitter sends constant high power sound forward. Does not locate receivers and does move the beam. Does not ever stop transmitting. If you place a receiver in front of it, it can turn on an LED at ~1 ft. They say its all made out of commercially available components and is ready to go to market. The receiver can move an inch or two sideways and still works. --- End quote --- Just the 1 LED? :-DD --- Quote from: PaulReynolds on March 11, 2019, 03:50:06 am ---I would be very surprised if that LED detector did not have batteries in the frame to amplify any received signals, I've thought that they were only using that to show the beam, not to actually claim it's self powered. Were they actually claiming that was all from energy harvesting, no batteries? --- End quote --- I used to think the LED boards didn't have batteries but after the mac CES video I think the large one does now! 1TX > 0.5m > 1RX > 1LED is impossible, I've tried it and only goto to about 7mm with 30Vpp on the TX. |
| sdpkom:
--- Quote from: StillTrying on March 11, 2019, 10:36:13 am --- Just the 1 LED? :-DD --- End quote --- Not 1, about 24X26 of them...., but only about 30% are lit at any time. Assuming each LED is ~5mW LED, if all the LEDs were lit @ full power it would mean ~1+W of power. About 30% of them are lit, at best, and most of the one's that are lit are dim (dim=10% of power), so I would say we're seeing here 50-200mW of electrical power going into the LEDs, at ~ 1 meter distance. The spot seems like a ~100 cm^2 spot, assuming some 25% conversion efficiency, you get 2-8mW/cm^2 of sound, or ~135-140dB @ the receiver. @paulReynolds can probably estimate this much better. |
| PaulReynolds:
--- Quote from: sdpkom on March 11, 2019, 03:39:21 pm --- --- Quote from: StillTrying on March 11, 2019, 10:36:13 am --- Just the 1 LED? :-DD --- End quote --- Not 1, about 24X26 of them...., but only about 30% are lit at any time. Assuming each LED is ~5mW LED, if all the LEDs were lit @ full power it would mean ~1+W of power. About 30% of them are lit, at best, and most of the one's that are lit are dim (dim=10% of power), so I would say we're seeing here 50-200mW of electrical power going into the LEDs, at ~ 1 meter distance. The spot seems like a ~100 cm^2 spot, assuming some 25% conversion efficiency, you get 2-8mW/cm^2 of sound, or ~135-140dB @ the receiver. @paulReynolds can probably estimate this much better. --- End quote --- There are so many unknowns now in what they are doing, and inconsistent reported statements from them, it's getting hard, even for me, to make good estimates as to power levels, however I'll return to the point I made earlier that I had assumed that the LED detector panel was not 'self powered' and instead had batteries to amplify any incoming signal. That would be pretty simple to have a board with a M by N grid each with an amplifier, a Murata receiver on one side, and an LED on the other. If it's self powered you'd see that really quickly with distance. They also wouldn't be doing demos where they use a small panel to light a single LED, as I heard they did at CES in the private show, if each Murata could light a single LED. I'm not even sure what they are doing now, it just doesn't make sense to me, not even in a "lipstick on a pig" way. If you can do 1 Watt at 1 meter, show it, it's 33x better than Energous. If it's certified safe, release the study and prove it. If it's legal in a country you can say "under <insert dB limit here> at all points". If you can't charge for shit (kinda important), if it's not safe, and if it isn't (or you're not sure) that it's legal, then you might want to rethink your business plan and pivot PDQ because things aren't going to get better from here. Basically, IMO, if they had what they're apparently claiming, it makes complete sense to go public with it all. That they don't is pretty telling. |
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