FCC approves first 'power-at-a-distance' wireless charging device

Why not use 2.45 GHz at a couple watts and use it to charge batteries AND warm up food?
(For those of us licensed after the beginning of the current millennium, the above was meant as sarcasm.)

This general idea is about as dumb as Tesla's broader dream of wireless power distribution. I'm imagining young children developing brain tumors before they reach school age. On one hand, we have people panicking over cell phone ERP. On the other hand, similar-minded folks think PaD is a great idea. I for one, think this concept has a very high danger to convenience ratio and isn't even worth the research it would take to investigate its practicality for home use.

 

I might imagine, he's smiling for the same reason Bob is....

 

Just cuz something is patented, don't mean it's a great idea...

http://totallyabsurd.com/absurd.htm
http://www.cracked.com/article_15693_the-10-most-ridiculous-inventions-ever-patented.html
http://listverse.com/2009/05/07/10-more-extremely-bizarre-and-pointless-patents/

 

And after all, isn't that the most important thing to today's young tech-crazed, brainless, short sighted, easily impressed, 'can't wait for the future', trophy just for showing up, millennial consumer?

 

Not relevant. The point is that if you look at the patents, you can see how their system works.

 

Sure it is... and funny too.

The point is, just because something is patentable and functional, doesn't mean that it's a good idea, nor does it guarantee that it will catch on and be popular or profitable... If it were so, we would all be wearing fart proof underwear.

 

Nope. I couldn't care less about that. The objective of a patent is to claim a novel invention and teach the art of making it. I read other folks' patents to have them teach me that art. Whether a minuscule fraction of issued patents is 'foolish' or not is irrelevant to me. I don't read foolish patents. In fact, I have never run across one in 35 years of patent searching. Guess my interests don't coincide with ones that lend themselves to foolishness.

I am not interested in learning that. I'm not interested in every QSO on the ham bands either. Surely we must concede that a non-trivial fraction of those are foolish, too.

Obviously you must be interested in mitigating the aroma of flatulence or you wouldn't have brought it up.

Frankly, that concept doesn't rock my world. As I approach 63 I am only interested in solving real problems, and my digestive tract is in unusually good shape, thanks to psyllium, carrots, and proper bacterial flora.

The patent library is the most important source and documentation of progress in the human condition.

 

Patent no patent , I am from Missouri , show me state.
No more voodoo guess work.

Assume that the wireless charger spec is to TRICKLE charge with 1 mA current and we still have contains of 1W RF output and load located 3 feet ( app 1 meter ) from the source.
Show me the intensity of RF - measured by microvolts per square meter at the distance of 1 meter.
Show me , with measure units of you choice , "level " of RF at the receiving antenna terminal.
Show me the rough outline of the "power converter" using measuring units of your choice at the OUTPUT of the "converter".
Does the output meets the spec required 1 mA of trickle charge?

As a bonus question - show estimated efficiency of each component of this setup.

I am too old , OK lazy, to do this high school math.

73 Shirley

PS As far as I know obtaining a patent DOES NOT require actual demonstration of the "idea".

 

Ideas are not patentable.

Patents are all subject to the requirement of enablement.

 

Wow... You may be a brilliant physicist, but you apparently know nothing about the human condition... and don't even realize it.

 

Sometimes, I wish I knew a lot less.

But nice try anyway.

 

OK, I used wrong word.
Let's use different word since English is such rich language - what is the subject of this "patent" in general?
Or - do you have a real patent number so I can laugh at my own leisure?

As far as "enablement" - if Henry Ford had a patent on Model T it enabled to convert can of gas to few miles of road passage.

In this case we are trying to "enable" 1 mA of current into a battery.
Compare to Henry's patent it is child's play.

73 Shirley

 

Shirley,

I am just informing you a bit on how patents are set up. Enablement is a basic patent term.

I dont define the ground rules.

On the OP topic, I guided us to look at the patents, to see how the charging system works. Thats all.

73
Chip W1YW

 

However convenient wireless charging of devices "up to three feet away" the laws of physics clearly show an inverse square signal loss so that even at 900 MHz a device being charged at 3 feet is approx. three wavelengths away and will only receive a fraction of the transmitted power. This means the power the consumer takes from the supply will be vastly more than the power transferred to the wireless device. What's the point of that when most of us are trying to reduce energy consumption and be a little more green in our approach to energy use. Basically don't be so lazy plug just phone in the wall to charge it and save energy!

 

I do want to correct a naive rule of thumb that many people invoke on the Friis Equation. So this is a generic response to the post, and not targeted at any person.

First, the Friis equation only applies to the far field. That means that moderate or high gain antennas require a minimum distance before it applies, and that distance is not 1/16 or 1/2 wave--it depends on the apertures used. Next, the medium is not invoked in the Friis equation. So you've got that attenuation to deal with.

The naive rule of thumb on the Friis Equation is that the received power goes down dramatically as the frequency goes up. Well, sure, if there is no wavelength dependence on the antennas. IOW if you choose antennas of a given gain, and don't change the gain(s) with increasing frequency, the rule of thumb applies.

But it is a bad rule of thumb. Here why: the antenna gains INCREASE, for fixed apertures, as the frequency increases, even though the NUMERATOR lambda-squared term applies.

Want to see that dependence? It may surprise many (unless you took a signals and systems course in college):

Gain = 4 pi Ae/ lambda-squared

Ae= pi D squared/4 (roughly, for an assumed circular aperture, diameter D)

If D is fixed then

Gain=k/ lambda-squared where k is a constant

And, as a good example, if you have the same antenna apertures at RX and TX, then

Gt =Gr

So in the Friis equation, you end up with a factor of lambda -squared IN THE DENOMINATOR, with NO lambda factor IN THE NUMERATOR.

IOW, the received power GOES UP as you increase frequency.

It always disappoints me that we tend to take even simple equations linke the Friis equation and relegate them to boxes on an excel sheet, without thinking about what the equations MEAN anymore:-(

Pity.