Apple has acquired a privately-held low-power Bluetooth specialist called Passif Semiconductor. Not a lot is known about the company, which Business Week describes as a manufacturer of “switch-based wireless transceivers with low power consumption and a small footprint” that was incorporated in 2007. It's also known that the …
wireless ibutton then?
Sounds like the ibutton system of Dallas, but wireless. The ibutton will also charge an internal capacitor from its only connection line (apart from ground), and use that to power itself when the lines is used for communication.
I thought the wireless equivalent had already been thought of elsewhere?
This just sounds like a wireless version of telephone line power theft to me. Company A sets up a microwave comms unit, company B designs a way to suck the power out of that signal. Company A then has to up the power.
No such thing as a free lunch!
This is nothing like sticking a big coil of wire underneath a big power line running over your property for "free" electricity (I assume that's what you meant by "telephone line power theft") In that case the power is supposed to stay on the wire, and one takes advantage of the fact that not all of it does and uses that wire to encourage more of it to leave the wire than would have otherwise been the case if that wire was not there. Thus the generator needs to increase its power to cover what you're stealing.
In the case of cellular, wifi or bluetooth signals, the power is not supposed to stay on the wire (i.e. antenna) but to be radiated into the air. Once it is in the air it makes no difference to the transmitter whether it is received and used as intended, received and used for some miniscule scrap of power, hits something resulting in a tiny increase in that something's temperature, or radiates into outer space. The transmitter power stays the same regardless of which of those four fates awaits an individual photon emitted by the antenna.
No, I meant running electronic things in your house from the power coming over your phone line. With WAN links there is quite a bit of power too!
That would be a capacitor (physical device), with a undetermined value of capacitance (charge storage ability)
Microwave light bulb
No, there will be a market soon for a continuous microwave source, so that battery-less devices can be powered parasitically.
Pubs and hotels will display a special logo (I was going to say "black power", but that;s been used. "dark energy"? nope - also spoken for). "Stray energy" perhaps?
Then the foil-hatters can sell allyhats to thousands of people to wear in their own rooms.
My water meter has had one on these type of devices for years so that the water company can read the meter without removing the inspection cover.
Re: What's new?
How long does it take to collect the reading? Just a matter of pointing the instrument towards the meter, and off you go?
Here in Guptastan (formerly Gauteng) they do it the old-fashioned way - open the cover for inspection. Frequently the oke doing the inspection get his numbers mixed up, leading to billing chaos.
We email our 'leccy and water figures in to the loonicipal offices every month to avoid a cock-up on our bill.
Re: What's new?
They just point their magical device in the direction of the meter (which is about 200cm below ground level) press a button and job done. If fact I have two meters side-by-side so another button press reads the second one. I have never had a problem with wrong readings (I can check the physical meter by lifting the cover and peering down the hole with the help of a flashlight and read the numbers off the mechanism).
Having just run down the battery on my heart rate monitor's chest strap, I am intrigued by the prospect of never having to change the battery on such a device.
...would it be until somebody misinterprets the "charging by microwaves" part and consequently nuke their iFondle-device in a popular meal cooking device?