Wireless Charging

[InfiniteNow]

it is not made there, but arrives there as a component of the broadcast signal.

 

in the event the claim is laid that we differ only philosophically on this, i claim the stronger argument so far. :hihi:

 

Pssst... Hey... Freeztar... Hit him with this one... :rant:

 

 

It's actually the outcome of localized quantum fluctuations in aggregate. ;)

 

 

My refrigerator scribbles are unidimensional strings. :)

[Jay-qu]

I dont know if you can say they are one in the same - but they are definitely similar and interchangable.

 

Electricity as we know it is the movement of charges through an electric field, this movement creates a magnetic field. When AC current is used the constant chaging will cause electro-magnetic waves to be created. Which will go off in all directions. When these waves encounter free to move charges, like in metals, it causes them to move..

[freeztar]

i will argue it is the same. where there is electricity, there is magnetism

 

One and the same?

 

...and where there is magnetism and moving conductors there is electricity.

 

Agreed.

 

all the apparatus we use to manipulate electro-magnetic radiation is ultimately involed in controlling the circumstance in order to deliver a specific form. the electrical component of light and radio may seem small compared to say house-current, but it's there nonetheless. it is electricity that flows in the antenna, pure & simple. it is not made there, but arrives there as a component of the broadcast signal.

 

Electrons...

Yes, there is an electrical component to every electromagnetic radiation. But this is not the same as electric current, which is what I assume the OP meant, rather than weak radio transmissions that need amplification and are unsuited for "electrical transfer" at this point in time.

 

in the event the claim is laid that we differ only philosophically on this, i claim the stronger argument so far. :hihi: :omg:

 

"That's just..like....your....opinion man" - The Dude from "The Big Lebowski"

:hihi:

[Turtle]

Electrons...

Yes, there is an electrical component to every electromagnetic radiation. But this is not the same as electric current, which is what I assume the OP meant, rather than weak radio transmissions that need amplification and are unsuited for "electrical transfer" at this point in time.

 

 

 

"That's just..like....your....opinion man" - The Dude from "The Big Lebowski"

:hihi:

 

:hihi: :hihi: so it is. :D so then...on the bold; would your position change if the radio signals are strong? or perhaps depending on the frequency? :cup: :omg:

Microwave electric power transmission. A bibliography with abstracts

[freeztar]

:hihi: :hihi: so it is. :D so then...on the bold; would your position change if the radio signals are strong? or perhaps depending on the frequency? :cup: :omg:

Microwave electric power transmission. A bibliography with abstracts

 

Cool link, I wish I could read the whole article. :(

 

So, what's my position again? :D

But seriously, I'm just trying to wrap my head around this stuff. Electricity has always been elusive to me for some reason.

If I plug my lamp into the wall socket in my house, then could the energy coming through the wire be labeled "radio"? Why or why not? To me it would seem that it could be called radio because it is electromagnetic, but on the other hand, the more popular nomenclature for radio prefers a band of the electromagnetic spectrum. Is this a semantics issue? :hihi:

 

But to get back to your questions, I would definitely give more credence to a microwave transmitted power system rather than a radio transmitted power system.

[Turtle]

Cool link, I wish I could read the whole article. :D

 

So, what's my position again? :D

But seriously, I'm just trying to wrap my head around this stuff. Electricity has always been elusive to me for some reason.

If I plug my lamp into the wall socket in my house, then could the energy coming through the wire be labeled "radio"? Why or why not? To me it would seem that it could be called radio because it is electromagnetic, but on the other hand, the more popular nomenclature for radio prefers a band of the electromagnetic spectrum. Is this a semantics issue? :hihi:

 

But to get back to your questions, I would definitely give more credence to a microwave transmitted power system rather than a radio transmitted power system.

 

i'll find an article with more discussion on microwave power transmission. i agree the topic is ellusive; moreover it is in many respects, allusive and illusive as well. :hihi: getting back to the question, microwaves according to these sources are classed separately from radio. :hihi: yes, common usage often belies the full extent of the electromagnetic spectrum, making for a semantics issue. this dictionary gives this range of frequencies for 'radio' >>radio - definition of radio by the Free Online Dictionary, Thesaurus and Encyclopedia.

1. The wireless transmission through space of electromagnetic waves in the approximate frequency range from 10 kilohertz to 300,000 megahertz.

 

this page says this about EM radiation. >> Safety and Health Topics: Radiofrequency and Microwave Radiation

Radiofrequency (RF) and microwave (MW) radiation are electromagnetic radiation in the frequency ranges 3 kilohertz (kHz) - 300 Megahertz (MHz), and 300 MHz - 300 gigahertz (GHz), respectively.

 

regardless of these semantic issues, it is all electric phenomena. :cup: :omg:

[freeztar]

Cool, with the semantics out of the way and my acceptance of it all being electromagnetic phenomena, where were we?

 

I guess the big questions now are, What does this microwave power transmission have to offer and can it be accomplished on a small scale?

[InfiniteNow]

I guess the big questions now are, What does this microwave power transmission have to offer and can it be accomplished on a small scale?

 

Implantable insulin pumps which can be "recharged" by simply standing next a wireless energy source?

 

Implantable brain chips like BrainGate on a much smaller scale... could just wear a hat to charge it up.

 

Put it in the floors of those who have powered wheelchairs.

 

Put it in the garage of those with battery powered cars.

 

I don't know... I got nothin'.

[Turtle]

Cool, with the semantics out of the way and my acceptance of it all being electromagnetic phenomena, where were we? :doh:

 

I guess the big questions now are, What does this microwave power transmission have to offer and can it be accomplished on a small scale?

 

microwave power transmission offers the ability to capture sunlight in space with photo-voltaics on satellites and then beam the electrical power to Earth. electricity can be delivered where needed without running wires and/or fed into existing electrical grids therefore reducing the amount of fossil fuels used to generate electricity. given the expense of sending payloads into orbit, this application makes little sense on a small scale. the best i could find after that abstract is a wicki article; i searched 'microwave electrical power transmission'. >> Microwave power transmission - Wikipedia, the free encyclopedia

[freeztar]

I found this link from that wiki link you posted:

Publication IAF 97

 

That seems pretty small scale to me, and very interesting indeed.

[Jay-qu]

This topic more becomes - how can energy be wirelessly transported rather than how electricity (in the form of electrons) can be. And the answer to that is photons - as pointed out by microwave transmission. A rectenna (microwave antenna) can acheive efficiencies up to 90% in optimum circumstances. So what are the other problems with having microwaves bouncing about the place?

[Turtle]

I found this link from that wiki link you posted:

Publication IAF 97

 

interesting. the proposal is 10 years old; i wonder if they ever built it?

 

This topic more becomes - how can energy be wirelessly transported rather than how electricity (in the form of electrons) can be. And the answer to that is photons - as pointed out by microwave transmission. A rectenna (microwave antenna) can acheive efficiencies up to 90% in optimum circumstances. So what are the other problems with having microwaves bouncing about the place?

 

ummmm...i don't get your drift. what other 'energy' is transported in wires other than electrical? why does microwave transmission point to photons? (other than both are electromagnetic radiation that is). the problem with having microwaves bouncing around is that they damage living tissue, and the danger is compounded when the power is ramped up. the little screen in your microwave oven door is there to protect you from the radiation, and that's only 600w to 1200 watts of power.

 

Tesla's scheme on the other hand was to charge the entire atmosphere using large transmitting domes, and draw it off with receivers wherever power is needed. at one point, even he expressed concern it could ignite the atmosphere.:doh: at any rate, he lost funding and his equipment was torn down. >> The Tesla Wardenclyffe Project

:D

[Jay-qu]

Im just saying that to transmit energy using microwaves is to be be transmitting energy via photons - photons of EM radiation that corresponds to a wavelength in the micro meter range. Technically photons would transport the energy in electrical currents, as photons are the mediator of the EM force.

[CraigD]

The major difficulty with designing a long-range wireless power transmitter is, I think, avoiding resonance in conductors other than the target antenna. Radio transmitters can be very high power, producing high power in their receivers, but also in various unintentional antennas, like printed circuit boards and metal keys, wiring, nails, etc. An antenna is tuned to resonate at a particular frequency by adjusting its physical length and factors such as its capacitance and resistance, allowing a resonating antenna for a particular radio frequency to be many possible physical sizes – handy when you’re trying to receive a very weak signal in a compact device, troublesome when it occurs in various common (and unpredictable) items in the presence of a super strong signal. I’ve visions of all of my personal electronics staying nicely charged, but my zipper getting hot enough to sing my drawers! :cup:

 

The difference between transmission via radio antennas, and induction, via closely placed coils, is interesting. Antennas emits RF photons into space just as a glowing filament emits IR and visible light photons (unlike filaments, it’s practical to place multiple transmission antennas so that they emit their photons mostly in 2 directions – handy for pointing radio signals at population centers.). It’s power is independent of the power drawn by any receivers. With an induction coil, the power depends on the presence of the “receiver” coil. This is why, when I unplug my laptop from its power supply - which is basically just an transformer, a form of inductive power transmitter – although it continues to generate a moving magnetic field, it draws almost no power.

 

The physics behind this has something to do, I think, with real photons, in the case of a radio transmitter, and virtual ones, in the case of the ones responsible for the induction coil’s magnetic field. My understanding of this distinction is so vague and informal, it seems a bit mysterious to me. :clock:

[freeztar]

when I unplug my laptop from its power supply - which is basically just an transformer, a form of inductive power transmitter – although it continues to generate a moving magnetic field, it draws almost no power.

 

Can you elaborate on this Craig? I'm having trouble understanding the last comment, "draws almost no power".

[CraigD]

Can you elaborate on this Craig? I'm having trouble understanding the last comment, "draws almost no power".

Consider a typical transformer, similar to the one in a laptop power supply. If the secondary circuit has a non-zero, non-infinite resistance, the primary circuit will also, and will thus require power. If the secondary circuit has zero or infinite resistance (is unplugged or switched off), the primary circuit will have nearly zero resistance, and thus nearly zero power.

 

This is why it’s not necessary to unplug a laptop power supply to avoid running up your electric bill, just turn sleep, hibernate, or turn off the laptop. My ever-handy Kill-A-Volt meter reads around 48 W with my iGo power supply plugged into my unremarkable laptop, 0 W with it unplugged (the iGo’s little LED power light on it draws too little power for the meter to register). Similarly, I expect that the Wildcharge “charging mat” Jay-qu introduced in post #1 would draw 3-5 W with a typical mobile phone (well, not typical, as it must have an inductive charging coil built in, a feature I’ve yet to see on the market) set on it, then drop to nearly 0 when the phone was removed.

[Jay-qu]

from wiki

 

Hidetsugu Yagi attempted wireless energy transfer in February of 1926 with [the yagi] antenna. Yagi and Uda published their first report on the wave projector directional antenna. Yagi managed to demonstrate a proof of concept, but the engineering problems proved to be more onerous than conventional systems.

Yagi antenna - Wikipedia, the free encyclopedia

 

apparently another method of wireless transmission is via Evanescent wave coupling, and this is whats used for the electric toothbrushes :D