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An Inventor Wants One Less Wire to Worry About

nytimes.com

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Re: An Inventor Wants One Less Wire to Worry About

#61

Post by acadien »

alexhawdon wrote: post #33
tocomment wrote: post #28

Here's what I've been wondering. A transformer provides very efficient wireless power transmission but on a few centimeters. Has anyone considered scaling up a transformer? Would that increase the range? What if we made a house sized one and buried it under the house? Could that provide wireless electricity to the whole house?

You're talking about inductive charging, which is basically how electric toothbrushes charge. It's recently been built into new devices (my Nexus 4 supports it) but obviously requires they be placed on a charging mat/station. Perhaps in the future it could be built into desks, so that everything placed on them charges. I would imagine (but I'm no EE/physicist) that these get terribly inefficient when you scale them u…

I've heard the palm-pixi charging stand (which can be easily hacked to charge many other cell phones[1]) gets roughly 70% efficiency.

[1] http://hackaday.com/2013/06/19/adding-wireless-charging-to-a...

Re: An Inventor Wants One Less Wire to Worry About

#62

Post by Gravityloss »

greenyoda wrote: post #41
lreeves wrote: post #38

Earlier quoted context omitted.

If it actually works it'll inevitably be miniaturized over time I'd imagine, pretty much like everything else in technology.

Electronics have gotten miniaturized, but that doesn't mean that a mechanical device that generates sound vibrations can be miniaturized. For example, an iPhone contains the computing power that used to take up a large room, but we don't have loudspeakers that are 0.01 inches in diameter and deliver the same sound output as conventional ones.

but antennas have been miniaturized very well. (Frequencies have gotten somewhat higher, but it doesn't explain everything.)

Re: An Inventor Wants One Less Wire to Worry About

#63

Post by ihavedna »

vacri wrote: post #50
doctorpangloss wrote: post #18

Did she have a hard time finding investors because it was a hardware business, or because she was a woman? Did she ultimately get investment because she was a woman, in spite of the hardware business? According to a friend's college thesis, there are lots of concrete reasons VCs don't invest in women.[0] In summary, VCs don't take a girl very seriously. The thesis makes the case though that there's real opportunity f…

I've always found it odd that people talking about sexism use 'woman' like it's an adjective. Common use has made it one, but it used to be just a noun. Anyway, my point is that we don't say "man founders" or "man drivers" or "men professionals".

It is because woman are considered to be the adjunct, not the norm, not the average, not the expected or assumed. Its even obvious in the word itself - a prefix on the word "man", which can and is often used in place of "person" or "human", and will describe a person who is more than likely assumed to be of the masculine persuasion.

A+ on not putting "Woman" in the headline for the article, though!

Re: An Inventor Wants One Less Wire to Worry About

#64

Post by greenyoda »

Gravityloss wrote: post #62
greenyoda wrote: post #41

Earlier quoted context omitted.

Electronics have gotten miniaturized, but that doesn't mean that a mechanical device that generates sound vibrations can be miniaturized. For example, an iPhone contains the computing power that used to take up a large room, but we don't have loudspeakers that are 0.01 inches in diameter and deliver the same sound output as conventional ones.

but antennas have been miniaturized very well. (Frequencies have gotten somewhat higher, but it doesn't explain everything.)

Antennas aren't mechanical devices; they don't need to transfer mechanical energy to air molecules. Also, their size is constrained by the power they need to emit as well as the wavelength of the signal, so we aren't going to see a cell phone antenna that's on the same scale as a transistor in an integrated circuit (tens of nanometers). An antenna that can only put out a microwatt of power won't be able to hit a cell tower that's a couple of miles away.

Re: An Inventor Wants One Less Wire to Worry About

#65

Post by eCa »

vacri wrote: post #50
doctorpangloss wrote: post #18

Did she have a hard time finding investors because it was a hardware business, or because she was a woman? Did she ultimately get investment because she was a woman, in spite of the hardware business? According to a friend's college thesis, there are lots of concrete reasons VCs don't invest in women.[0] In summary, VCs don't take a girl very seriously. The thesis makes the case though that there's real opportunity f…

I've always found it odd that people talking about sexism use 'woman' like it's an adjective. Common use has made it one, but it used to be just a noun. Anyway, my point is that we don't say "man founders" or "man drivers" or "men professionals".

Me too. I've always thought male/female is a better fit (English not being my first language).

Re: An Inventor Wants One Less Wire to Worry About

#67

Post by aaron695 »

I cannot see in a world were we are trying to reduce energy use how wireless power is possible?

Even if it's got some sort of feedback that allows it to be a highly concentrated beam between devices it still seems to me it'll be very lossy.

Loss in the air. Loss in transforming the energy twice more than normal.

Re: An Inventor Wants One Less Wire to Worry About

#68

Post by etrautmann »

svantana wrote: post #23

I wonder about the health aspect of this. It seems there is very little known about long-term exposure to high intensity ultrasound. Also, there could be a risk of ear damage if a non-linear material came into the sound field, and producing distortion artifacts in the audible frequency range - given that about 1W/m^2 can be enough to cause damage.

It can't actually harm your hearing, by definition. Hearing damage caused by high intensity sound is the result of mechanical transduction of sound waves to hair cells in your inner ear. When the amplitude of a certain frequency is too high, the cells responsible for turning those mechanical vibrations into electrical signals are physically damaged.

Ultrasound is mechanically filtered, so it can't propagate into your cochlea and damage the hair cells. This is in contrast to something like photons, where UV or infrared light can absolutely damage your photoreceptors in your eye.

Re: An Inventor Wants One Less Wire to Worry About

#70

Post by etrautmann »

EEGuy wrote: post #59
svantana wrote: post #23

I wonder about the health aspect of this. It seems there is very little known about long-term exposure to high intensity ultrasound. Also, there could be a risk of ear damage if a non-linear material came into the sound field, and producing distortion artifacts in the audible frequency range - given that about 1W/m^2 can be enough to cause damage.

This, svantana. My dentist's ultrasonic dental plaque removing tool produces audible squeals reminiscent of analog tuning of an AM radio. That's one possible example of probable nonlinearities (in my gums an teeth) producing detectible audible power from ultrasonic energy transmission. No reference -- it's just what I hear every time I have my teeth cleaned. Granted an ultrasonic water stream (dental application) has…

It doesn't even have to be nonlinearities, could also be sidelobes of the fundamental ultrasound frequency. There's no reason to filter those out if it's not harmful, which I'd like to think was carefully verified.
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