Researcher has developed, at a cost of less than one dollar, a wireless light switch that runs without batteries, can be installed anywhere on a wall and could reduce the cost of wiring a house by …::A U of A engineering researcher has developed a wireless light switch that could reduce the cost of wiring a house by as much as 50 per cent.
That is mind-blowing.
Last time i saw a product claiming to run on energy harvested from radio-waves, it was a kickstarter project that (surprise surprise) turned out to be a complete scam.
It is totally possible to harvest energy from radio waves, it’s just such a tiny amount that you could barely light a LED
Yeah that’s my point, the energy you can actually harvest is ridiculously small. Even if it was slowly charging a capacitor with this harvested power and saving it for later use, how often can i use the switch before depleting the energy faster than it charges? “oh sorry, you’ll have to wait 5min to turn on your lights again, It’s not quite charged enough”
My guess is you would get a couple seconds of light before needing several hours to charge it up again.
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I’ve heard of this before but I think it’s really a trickle charge. Not practical for charging a phone or anything like that.
I have a Philips Hue wireless switch that has no batteries. The click action when you press the button is enough to drive the transmitter. The button moves in about 4-5mm when pressed and that is all that’s needed to drive the transmitter.
What’s really mind-blowing is that such trivial amounts of energy runs a transmitter that sends a specially coded pulse (not even just an on off pulse of RF) thirty feet to the receiver.