News Nintendo Switch Joy-Cons Get Over the Air Charging with Powercasts

Aug 26, 2020
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Where is the room-scale wireless charging? The History Channel said tesla invented wireless electricity back when he was alive. Lol

He invented it but he also invented death rays. He invented a lot of stuff that never exists, that can/should never exist.

I'm of the opinion that while that could work it would have crap efficacy.
 
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livingbriggs

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It does exist. Tesla demonstrated it was possible, and others have done it. but as NJM1564 has speculated, efficiency is crap. I believe theoretically it's sitting at like 50% at super low wattage and requires pinpoint direct line of sight. New Zealand has a company experimenting with long range transmission, Emrod, but it's a startup that, like all recent tech startups, will probably just run with the money while delivering empty promises.

EDIT: But I do hope in my lifetime someone figures it out, even if just for keyboard and mouse. Never needing to worry about plugging them in ever again would be sweet.
 

samopa

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EDIT: But I do hope in my lifetime someone figures it out, even if just for keyboard and mouse. Never needing to worry about plugging them in ever again would be sweet.

Logitech already has this technology for their G series Mouse called PowerPlay.
I had never charge my mouse since I bought that. I don't even bother to turn off the mouse when not using it (it automatically turn off when idle for some period).
I'm using (now) Logitech G703 as my primary mouse and sometimes (when needed) switch to G903 mouse for gaming. Both of them support PowerPlay.
 

Endymio

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I believe theoretically [efficiency is] sitting at like 50% at super low wattage
You can do much better than that if you're willing to design in the expense of an RF (or higher frequency) laser. But in any case, when you're talking about the minimal power draws of peripherals such as this, efficiency isn't really a consideration.
 
He invented it but he also invented death rays. He invented a lot of stuff that never exists, that can/should never exist.

I'm of the opinion that while that could work it would have crap efficacy.

He actually did have working examples of wireless charging and power delivery when he was alive. HOWEVER Tesla didn't have the theory (no one did) to prove it was inefficient.

Only now has theoretical microwave power beamed a long distance is a reality. (Satellites in space convert solar power to microwave energy which is focused on a receiver on Earth) It's not very efficient, but a reasonable way to deliver spot power to remote locations.
 

livingbriggs

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Logitech already has this technology for their G series Mouse called PowerPlay.
I had never charge my mouse since I bought that. I don't even bother to turn off the mouse when not using it (it automatically turn off when idle for some period).
I'm using (now) Logitech G703 as my primary mouse and sometimes (when needed) switch to G903 mouse for gaming. Both of them support PowerPlay.

I did not know about that, thanks for the heads up. It's good for my gaming setup, but it isn't quite what I'm looking for, I'd like to see room level charging for my entertainment system, that is currently a mini pc hooked to a tv. If I could just leave my keyboard in the couch pocket and never worry about the batteries being dead and having to plug it in, that'd be great. And yes, I realize that I'm obviously very lazy.

Also, I'm more of a fluid mechanics guy, so most of the electrical stuff is over my head.
 
Eh? We've had the theory to calculate this since the days of Maxwell's equations, circa the 1860s.

While the power emission pattern and general laws were known, the attenuation over long distances what was unknown AFAIK. Different frequencies operate with different characteristics with different materials. For example red light IOR is greater than other visible light and it has a tendency to scatter. While high energy microwave, x-ray, and some gamma rays can be directed more easily (edit: for higher energy transfer), they suffer more attenuation through certain mediums. The problem with higher energies freq. is they tend to interact with everything causing ionization. (At least this is my understanding from a layman's engineering standpoint. Thermo, Aero, programming and basic electronics are my specialty not the black art of communications and EM energies.)

Tesla was a giant. He had a passion, for which I admire him. It's the dreamers of this world that create new things. His creative vision and ingenuity however seems to have out stripped his practical theoretical knowledge. He was more of a very gifted engineer with creativity than a true scientist.
 
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Endymio

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While the power emission pattern and general laws were known, the attenuation over long distances what was unknown AFAIK.
For RF propagating in free air, the old inverse-square law Newton used works fine.

...For example red light IOR is greater than other visible light and it has a tendency to scatter. While high energy microwave, x-ray, and some gamma rays can be directed more easily
Your premise was that Tesla couldn't calculate the efficiency of radio-frequency wireless charging because of theoretical issues. Now you're referring to engineering issues (viz. cross-sectional absorption data) for visible light and above.

The problem with higher energies freq. is they tend to interact with everything causing ionization. (At least this is my understanding from a layman's engineering standpoint.
Frequencies of UV and above do indeed cause ionization. But the relationship between absorption and frequency is much more complicated than a simple linear one ... else your doctor's x-ray machine couldn't take photos of the interior of your body. Another example is the NIR (near infra-red) frequencies that are used in fiber optic communications. Both higher-frequency visible light and lower-frequency infrared tend to be absorbed by the glass in the fiber; they operate in a wavelength "window" through which propagation can occur over kilometer-scale distances.
 
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