Yet another impractical wireless phone charging scam: Xiaomi Mi Air

[mikeselectricstuff]

https://www.gsmarena.com/xiaomi_introduces_mi_air_charge_wireless_charging_from_across_the_room-news-47461.php

[Haenk]

"it’s not known if such technology would ever make it to the consumer market"

And the "prototype" has the size of a small refrigerator, not sure if that's a new trend for your livingroom. Plus it only supplies 5W to your smartphone.

(It's probably not as "dodgy" as most of the stuff in this forum, just not a very practical technology, and they certainly know this...)

[Ice-Tea]

"it’s not known if such technology would ever make it to the consumer market"

And the "prototype" has the size of a small refrigerator, not sure if that's a new trend for your livingroom. Plus it only supplies 5W to your smartphone.

(It's probably not as "dodgy" as most of the stuff in this forum, just not a very practical technology, and they certainly know this...)

"Only"? If you can make that work as advertized, I have a billion dollars for you.

[Cyberdragon]

Xiaomi claims that physical objects don’t reduce the charging efficiency, but this must have some caveats.

Like, the thing most of these stupid "tech journalists" don't know called SCIENCE. Things like INVERSE SQUARE LAW!

[srb1954]

https://www.gsmarena.com/xiaomi_introduces_mi_air_charge_wireless_charging_from_across_the_room-news-47461.php

Looks like they have developed a domestic version of one of these
https://www.google.co.nz/imgres?imgurl=https%3A%2F%2Fwww.wired.com%2Fimages_blogs%2Fdangerroom%2Fimages%2F2008%2F10%2F10%2Fads_desert_2.jpg&imgrefurl=https%3A%2F%2Fwww.wired.com%2F2008%2F10%2Farmy-ordering-p%2F&tbnid=--ONWaWUOvno1M&vet=12ahUKEwjstJPZtcLuAhXBnksFHcq1DNAQMygNegUIARCoAQ..i&docid=yz2MrD2lSZ4yqM&w=385&h=262&q=microwave%20death%20ray&ved=2ahUKEwjstJPZtcLuAhXBnksFHcq1DNAQMygNegUIARCoAQ

[PlainName]

don't know called SCIENCE. Things like INVERSE SQUARE LAW!

The size of the box suggests they are doing phased array stuff, and the inverse square law doesn't apply to near-field. I believe that's science, but feel free to rant about how it's not.

[Marco]

I don't see how that's going to work with regulatory limits on mmWave exposure, ICNIRP has 2 mW/cm2 as their latest limit and regulation will likely be at that or less in any country. If your hand catches the outside edge of the beam it's easily going to be over.

[amyk]

I really don't see the point, unless this is some sort of satirical performance art --- has humanity gotten so lazy that people can't be bothered plugging something in?

[coppercone2]

the wireless charge bases are already pretty good

I still want like 50 of em so I can cook food laying on the kitchen table from 20 feet away, too lazy to clean the microwave. mm death ray

But I see where the designers are coming from, its just too hard to put a deck of cards in a designated square, its automate it with a mini sentry gun death ray.

Do these people just get wasted immediately after walking through the door and then have a problem calling in late for work the next day because they passed out on the floor with the phone in their back pocket? That's what this is trying to solve. The Line-of-site mechanism will lead to irradiated anuses even with all safety measures in place working correctly. Will there be a new generation of THz babies (like crack babies)?

Also what did we learn from Therac-25 about mechanical interlocks being necessary with beam energy sources? (it was basically a sentry gun that shot gamma radiation). I guess you still had to move a bore though, this just needs to face within like 45 degrees of you and it can lock on if the control system decides its appropriate.

[Marco]

It's still only on the level of bright sunlight and won't focus in the eye,  so not immediately dangerous ... but I still don't see how it would ever be legal.

[coppercone2]

a 10x10 panel of them would be pretty small and beastly

[PlainName]

has humanity gotten so lazy that people can't be bothered plugging something in?

That's a very backwards attitude, particularly one an engineering forum. Imagine if no-one ever bothered to make something just because they could, and nothing got designed unless there was already an overwhelming desire for the thing no-one knew they might, or could, use.

It's perfectly OK to say it won't work because blah blah. Or ask what problem it solves. Being sneery because you don't happen to like it is just having a closed and prejudiced mind.

Personally, I'd love it. Already pissed off with half a dozen USB leads on my desk and another set over there on the bench, and the phone having to be here or there and not on the other table over there. And that's without considering the issues of just plugging stuff in - the sales of wireless chargers indicate people don't want to dick around with tiny plugs. This thing, if it worked, would just be a natural extension of that - you would no longer need to leave your kit on exactly this spot, etc.

Good job the people that designed NFC never listened to you, eh.

[Shannon]

Lazy people provide demand, then engineers change the world！

[bd139]

Well no not really as most ideas seem to be outside the bounds of possibility. Actually my job has been mostly over the last three decades state repeatedly things like:

“Are you fucking serious?”

“You told the investors what?”

“No that’s actually impossible and no I’m not going to even go and try for a bit”

“Yes go and find someone else who can do it if I can’t”

“Did you bang your head before you opened your mouth?”

[Marco]

I really don't see the point, unless this is some sort of satirical performance art

Sometimes companies let their researchers take something extreme to prototype stage, nothing really wrong with that ... might find something useful along the way.

I think the Disney approach of turning an entire shielded room into a gigantic magnetic resonance chamber was an interesting approach too and not nearly as dangerous as people pretended. I suspect a wireless car charger working in the multi kW range will expose people to far stronger stray fields than the Disney room, yet those never get the same level of incredulity ... it's not going to couple to most things.

[PlainName]

Actually my job has been mostly over the last three decades state repeatedly things like:

Got to say that one of my most rewarding jobs (or, perhaps, satisfying) was one where the boss would promise some client that our product would of course do some feature we'd never considered. That would be on Friday and delivery the following week would be nice. I can't recall any time we failed to deliver, so perhaps the boss happened to know more about what was feasible with the stuff we designed than we did, which obviously didn't apply to your example situations.

There were a couple of times when I told him there was no chance, but then realised a way we could do it and did it anyway. The satisfaction quotient could be very high.

[AVGresponding]

don't know called SCIENCE. Things like INVERSE SQUARE LAW!

The size of the box suggests they are doing phased array stuff, and the inverse square law doesn't apply to near-field. I believe that's science, but feel free to rant about how it's not.

Indeed it doesn't.

NFC power levels drop off far more rapidly.     https://en.wikipedia.org/wiki/Near_and_far_field


EDIT: And any metallic object near either antenna will alter the resonance and therefore the efficiency, which will be laughably low even in ideal conditions. Go go global warming!

[Marco]

Anything further than a cm or so from the rectanna array is irrelevant, 5 mm wavelength.