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My little brother used to do electrical installations. He once set up a device that deactivated the power in a building as soon as no more consumers were on. Of
by mar77i 9y ago
My little brother used to do electrical installations. He once set up a device that deactivated the power in a building as soon as no more consumers were on. Of course that thing is probably still using power continuously itself.
On that same note, shouldn't it be possible to install a mechanism that doesn't use any power at all? Something like, uh, I'm not gonna say a light switch, but a weightless switch, to mix a few metaphors here.
- pjc50 9y agoIt consumes 8 nanowatts, which is well below the self-discharge rate of almost all batteries.
- jackhack 9y agoonly nanowatts? With an antenna, could this low level of power be drawn from radio/TV signals? It is enough to power a crystal set radio receiver.
- junkcollector 9y agoNanowatts are -60 dBm or what you would expect to receive on your cellphone when you have decent but not great signal. Many radios operate down to the -110 dBm/MHz PSD or lower ranges for high performance stuff. So you could use hits those power levels with energy harvesting on radio waves but only if you were in the right location, on the right band, and it would possibly cause problems for the systems that are trying to use those signals for their intended purposes.
- JoeAltmaier 9y agoAn RFID tag would do the job.
- ramzyo 9y agoYes, a passive wake up receiver is possible. See https://ip.sandia.gov/technology.do/techID=175 https://ip.sandia.gov/technology.do/techID=175