Student Invents Device that Charges Batteries with Radio and WIFI Waves
Posted by Kittyhawk 9 years, 8 months ago to Technology
German university student, Dennis Siegel, invented a device that captures electromagnetic fields like WIFI and radio waves and converts them to stored energy in batteries.
I'm skeptical about how much power you can get. I'd be shocked to see 1mW developed in a 50-ohm load. That works out to 0.22V, which is VERY hard to work w/ b/c it's less than a diode drop, BUT people are working hard on it b/c many of these energy harvesting ideas produce very low voltages. Even if the boost converter were 20% efficient, you would have 67uA at 3V. That's more than enough to run a small microcontroller with a 32kHz clock running that wakes up and does something at least once a second.
I'd love to here how Mr. Siegel boosts the voltage. That's were all the trickiness is. I love this topic.
Intel has been playing with AC-powered wireless charging for some time (at least since 2008), and Starbucks is deploying wireless charging for its customers beginning this year:
http://www.powermat.com/announcements/na...
My non-physicist understanding goes like this. At less than a wavelength range, inductive and capacitive coupling predominate. Over one wavelength, these effects drop off and the friis path loss equation starts to work. With inductive/capacitive coupling, you're transferring power out of the circuit. With EM coupling (path loss equation), you're picking up a tiny fraction of the radiated power that was going to shoot by your antenna and either deliver energy to something else or just keep going.
The problem with measuring voltage with a galvanometer is that the current generated is high frequency AC. You are, after all, converting radio waves. You'd probably want to rectify the voltage to do anything useful with it.
BTW, you can run an Atmel 8-bit core at 1 MHz on 210µA at 1.8V. Sleep mode takes just .1µA. So you could run a 30% duty cycle 1MHz processor on 67µA.
folks -- getting energy from the environment. Ben Franklin
started this.
except for inductive reaction (and the power company
catching you at it), you can harvest power from overhead
lines and never pay a cent. you can hear the sizzling
of the capacitive reaction in moist air when you
walk under them. just form a large loop of wire and,
zowie, measure the current -- and convert it!
the video on this site was withdrawn because of 3rd
party reports of patent infringement, it said.
if this works, with a high-frequency diode, the patent
will not do anyone much good -- all able
electronic tinkerers will do it. -- j
https://einstein.stanford.edu/content/re...
http://fas.org/irp/agency/dod/jason/grav...
gravity is a very-low-frequency (cycles per light-year)
wave, which we need an Einstein to translate ... and
I bet that there is one in here!!! -- j
Hmmm....
Gravitational EM waves would be absurdly high frequency if he's right
Ps - do you mean high frequency/long wavelength or short wavelength/low frequency. The original post by johnpe1 indicated he thought it was long-wavelength... (Wavelength * Frequency = speed of light)
http://www.blazelabs.com/pics/em_spectpl...
Here's a link to some of his writings on the topic:
http://www.blazelabs.com/f-g-intro.asp
But, that said, they would be so absurdly high energy it would be comical. The only way I can conceive on how they would be interacting with everyday objects without utterly obliterating them is that they NEVER actually collide with an object like gamma rays or other wavelengths do. But rather that they would simply interact by their passing near (I don't know if this happens or not), almost like a field.
Basically, if his theory were true, it would be a "push" theory, which explains action at a distance and a number of other effects. And it's also testable with extremely sensitive sensors (how sensitive I don't know). In short, massive objects would be "shadowing" gravity at some very small level. So you have "pressure" from one side where the massive object isn't shadowing, and "less pressure" on the side the massive object is shadowing.
In this case, gravity shouldn't "stack" with other objects, but would rather have diminishing returns. So if you stacked every planet in alignment, in theory (these are made up numbers) you would *expect* to see something like this (neglecting distance from the sun as a factor):
Gravity "pressure" near the sun, in the direction of the sun: 1.0
Gravity behind Mercury: 0.9
Gravity behind Venus: 0.8
behind Earth: 0.7
But in reality, since each object would be shadowing gravity, you're "losing" some strength from some gravity waves as they pass through the massive object. So maybe the gravity near the sun is only 99% of the "free space" gravity "pressure". So now you go to Mercury, and instead of 100% multiplied by Mercury's expected gravity, you only have 99%. And when you get to Venus, you only have 99% + Mercury's deletion of some of the gravity strength, maybe it's now 98%, etc... So by the time you get to Pluto, you may have a significant amount of gravity waves having lost strength, and could measure a difference in *actual* gravity vs "expected" gravity from today's theories.
This ALSO means there is a theoretical limit to gravity. It may be near impossible to get to, and may require way more mass than even a black hole could ever have, but, in theory, there would be a limit.
up during an eclipse, do we not feel the sum of the
gravity from both?
it seems to me that we can empirically dismiss the
"shadowing" idea...... my thought was and is that
gravity is a very long wavelength energy wave
which effectively has zero frequency in the inverse
square formula.
I just wish that we could finish what Albert went to
his death trying to do -- integrate gravity into his
equations. -- j
to one another in the nucleus is EM? -- j
Maybe you can explain what you mean.
A local unit (less than the size of a house) would be unlikely to generate more than enough energy to demonstrate the concept. Nothing useful.
Generated electricity (from your wall socket) costs about 12 cents per kWh, +/- 6 cents. For comparison, I'll use 12 cents.
If this device costs $8, it would take roughly 121 years using the device every day for 24 hours a day to break even on the purchase price… which is why this sort of technology isn't much used.
Assuming 10% methane, a daily volume of about 1/2 liter and an energy content of 55.7 kJ/g of methane, even disregarding the hydrogen in the mix, the average person expels slightly more energy in the form of farts than this device captures in a day (about 1.66 Wh/day versus 1.5).
So eat a few more beans.
rubbing the dog's fur? -- j