A post, each which connected without a wire, is it possible in a brief future?
Not in a significant way.José Ricardo said:A post, each which connected without a wire, is it possible in a brief future?
Of course. I "post" my electric toothbrush in its charger station every night. Not rocket science. Transferring significant amounts of power wirelessly over significant distances, um, no.José Ricardo said:A post, each which connected without a wire, is it possible in a brief future?
Do a search with Wireless Electricity Transmission.You will find many hits but there appears to be nothing that you can actually buy - except for the tooth brush charging system. There are various systems on the horizon for charging your personal devices on a table top but, to make them worth while considering, a smartphone manufacturer would need to be involved seriously with a compatible mod for charging a phone. But that is hardly more than another form 'non-contact' charging as with the tooth brush.José Ricardo said:A post, each which connected without a wire, is it possible in a brief future?
You can also power your radio from narrow-band energy in the AM radio spectrum...KenJackson said:Many years ago, Popular Science magazine had an article about a guy who powered his radio from the energy in a broad spectrum of ambient radio waves.
berkeman said:You can also power your radio from narrow-band energy in the AM radio spectrum...
Also the transponders in some car keys are contactless.CWatters said:Contactless smart card readers send wireless power over short distances and communicate both ways.
Well, with the fact that they can't even spell "Charging" in their video title, I'm skeptical as well...parsec said:What do you make of this? https://en.wikipedia.org/wiki/Resonant_inductive_coupling
That sounds like it should be a new thread. However, batteries are improving rapidly and research in energy storage for many purposes is a red-hot area. A good place to start is here: https://en.wikipedia.org/wiki/Search_for_the_Super_BatteryRonald Hamilton said:How can we make smaller lithium batteries.
Unproven Hypotheses, rather than Theories, mostly. And I am aware of his many failures. Full marks for the ideas about Electrical Power generation and distribution but there was an awful lot of dodgy, unproven stuff.Ronald Hamilton said:P.S. Are you familar with Tesla's theories?
parsec said:It feels like I'm missing something here. Why are inductive chargers for phones so relatively poor? Resonant inductive coupling circuits are quite simple, yet it was only discovered in 2006? Tesla spent many years trying to send power wirelessly at high efficiencies.
I can't help thinking that there is a flaw in the concept. A good resonance requires a High Q (quality factor), which implies low resistive loss. That means there can only be low Power involved. Passing significant power into a load would immediately kill the resonance peak.The demos that I have seen (like the Video above) show lamps being lit and modern LEDs are very efficient, showing lots of light and requiring very little electrical power input. The demonstrator used the term "Electricity" which puts his credibility as an Engineer, way down in my estimation.parsec said:Resonant inductive coupling circuits are quite simple,
essenmein said:The problem with "wireless" power transfer is something needs to carry the energy flux. That something is usually the magic of the electromagnetic force, unless by wireless transfer of power you are throwing mass at a thing that converts kinetic energy.
I would say we already take advantage of "wireless power", all radios work because the transmitter is sending a small amount of power to the receiver, its in probably in the u or nw range but none the less there is some power there other wise it wouldn't work. You wake up to wireless energy every morning. The giant ball of nuclear fire we orbit is transmitting oodles of power via the electromagnetic magic of photons to heat our planet and make electricity in solar panels.
If we want to reproduce that, we can, eg microwave beams and lasers. The problem is the energy flux, if you want to beam 1MW of power (ignoring inefficiency for now) you have 1MW micro wave beam, needless to say that would be problematic for anything crossing it, probably including air.
Doing it over large distances with something that cannot be focused will be immensely ineffective and inefficient while likely cooking everything in the vicinity, its what the sun is doing (~point source) so the portion of energy flux its throwing into space vs what we get is a number with a lot of zeros on the end of it, ie not something you would do if you had to pay to generate all that power.
Wires are just so much better at actually moving significant joules per second.
n=nanoJosé Ricardo said:What is the nw and u range?
Ahhh, I didn't realize it.essenmein said:n=nano
sophiecentaur said:I can't help thinking that there is a flaw in the concept. A good resonance requires a High Q (quality factor), which implies low resistive loss. That means there can only be low Power involved. Passing significant power into a load would immediately kill the resonance peak.The demos that I have seen (like the Video above) show lamps being lit and modern LEDs are very efficient, showing lots of light and requiring very little electrical power input. The demonstrator used the term "Electricity" which puts his credibility as an Engineer, way down in my estimation.
There was a video, some while ago, that showed a TV that, apparently, was powered from a coil, a couple of metres away. Nothing was mentioned about the power being transmitted or about the power being put into the transmitter. I must say that, if I had a really viable system to sell, I would say "Look. It is feeding 90W into that TV and the transmitter is only using 110W (or 95W?). As with all these schemes, no one ever seems to quote actual figures.
So it's not a lot better than my toothbrush!essenmein said:In wiki there was mention of a bus, but you read a bit more about that its got to park on a pad and then lower its receiving coil and then they got what 10kW across at something like 80%.
Klystron said:Two examples of wireless power transmission derive from RADAR systems:
- Given waveguide connecting the output of an amplitron tube to an antenna on the transmission side, many measurements are derived from transducers powered by energy extracted from within the waveguide such as a bolometer. Transducers are connected to externally powered collection devices such as oscilloscopes but the information gathering elements are powered by the EMF radiation.
Another example from RADAR science comes from the receiver sections of the system. Antennae and waveguides are often expensive devices designed to close tolerances based on fractions of the wavelengths (frequency harmonics, if you prefer) being transmitted and received. Practical RADAR installations share the physical components for the high-energy transmission with the low-energy reception. Delicate receiver components are protected during the high-energy transmission by anti-transmit-receive devices (ATR).
- Unguided radio frequency (RF) radiation induces measurable and extremely useful energy/signal in antennae cut to the correct fraction of the intended wavelength being transmitted. Practical applications include RADAR detectors and RF detection devices. The antenna signal can be filtered and amplified but the RF transmission powers the detector and, from an IT perspective, contains the desired information.
ATR devices are powered internally by radioactive isotopes but activated to "block" EMF by the energy of the transmission. Old Nick Tesla should have been pleased.
Interested students with access to RF transmitters and a micro-volt transducer such as an adjustable probe on an oscilloscope can experiment by creating an antenna from bare solid copper wire. Compute the optimal dimensions of the antenna, say based on an I(ndia)-band (previously X-band) transmitter. Clip the ends of the wire to shorten the length (or lower the temperature) while investigating induced voltage/current in your antenna. (Note: holding or touching the bare wire can effect results.)