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The commercial WiFi power harvester I remembered would be the perfect partner for a WiFi Spy. Despite the announcement that "on the CES floor, they were able t

The commercial WiFi power harvester I remembered would be the perfect partner for a WiFi Spy. Despite the announcement that "on the CES floor, they were able to charge a BlackBerry from 30% to full in about 90 minutes, using nothing but ambient WiFi signals as a power source. " [1] The device has never been turned into a commercial product. [2] [1] http://www.ohgizmo.com/2010/01/09/ces2010-rca-airnergy-charger-harvests-electricity-from-wifi/ http://www.ohgizmo.com/2010/01/09/ces2010-rca-airnergy-charg... [2] http://www.ohgizmo.com/2011/01/07/ces-2011-hey-rca-hows-that-airnergy-wifi-charger-coming-along-oh-no-where-to-be-seen-what-a-surprise/ http://www.ohgizmo.com/2011/01/07/ces-2011-hey-rca-hows-that...

DanBC 13y ago
You can make a very simple GSM signal detector using a germanium diode, an LED, and a bit of wire. Tune the wire by cutting it to the right length (a square with sides of 7.5 cm is fine) and solder the diodes in series. Hold a phone near it and send a text message to the phone. http://www.creative-science.org.uk/mobile_LED.html http://www.creative-science.org.uk/mobile_LED.html Of course, that's a tiny amount of power but it's still there to be harvested. Not sure what the legal situation is. In England an "artist" was asked to remove their installation of flourescent tubes in a field below power lines. They similarly harvested power. (I can't find that case using Google :-( but here are plenty of others https://www.google.co.uk/search?q=fluorescent+tubes+power+lines+field&sa=X&rlz=1RMGOYI_enGB573GB573&hl=en-GB&espv=1&tbm=isch&tbo=u&sboxchip=Images&source=univ&ei=dMFaU4r3EcGp7AbJ0IHoBw&ved=0CD0Q7Ak&biw=480&bih=300 https://www.google.co.uk/search?q=fluorescent+tubes+power+li... )
- SixSigma 13y ago
  I had a friend who was a phreaker here in the UK and was eventually arrested. At the time there was no Computer Misuse Act. They took hours to read out every "on this date did you make a call to the following number". He just sat in silence. Eventually he was successfully prosecuted for "Theft of Electricity" from the places he had placed unauthorised phone calls through.
- jmpe 13y ago
  Legal situation?!? You're creating a matched impedance point in space. RF energy harvesting is a bit of a hot topic, there are a number of modules on the market atm. Just search for it on mouser or farnell to get started. Thanks btw for that LED schematic, so simple. I'm currently tuning a harvester around a BQ25504 and super caps. I'll give it a test next week. http://uk.mouser.com/Embedded-Solutions/Energy-Harvesting-Modules/_/N-8t3zx?P=1yzotr6 http://uk.mouser.com/Embedded-Solutions/Energy-Harvesting-Mo... This one contains other energy sources as well: http://uk.farnell.com/jsp/search/browse.jsp?N=2002+225290&Ntk=gensearch&Ntt=energy+harvesting&Ntx=mode+matchallpartial http://uk.farnell.com/jsp/search/browse.jsp?N=2002+225290&Nt...

DanBC 13y ago

You can make a very simple GSM signal detector using a germanium diode, an LED, and a bit of wire. Tune the wire by cutting it to the right length (a square with sides of 7.5 cm is fine) and solder the diodes in series. Hold a phone near it and send a text message to the phone. http://www.creative-science.org.uk/mobile_LED.html http://www.creative-science.org.uk/mobile_LED.html Of course, that's a tiny amount of power but it's still there to be harvested. Not sure what the legal situation is. In England an "artist" was asked to remove their installation of flourescent tubes in a field below power lines. They similarly harvested power. (I can't find that case using Google :-( but here are plenty of others https://www.google.co.uk/search?q=fluorescent+tubes+power+lines+field&sa=X&rlz=1RMGOYI_enGB573GB573&hl=en-GB&espv=1&tbm=isch&tbo=u&sboxchip=Images&source=univ&ei=dMFaU4r3EcGp7AbJ0IHoBw&ved=0CD0Q7Ak&biw=480&bih=300 https://www.google.co.uk/search?q=fluorescent+tubes+power+li... )

SixSigma 13y ago
I had a friend who was a phreaker here in the UK and was eventually arrested. At the time there was no Computer Misuse Act. They took hours to read out every "on this date did you make a call to the following number". He just sat in silence. Eventually he was successfully prosecuted for "Theft of Electricity" from the places he had placed unauthorised phone calls through.
jmpe 13y ago
Legal situation?!? You're creating a matched impedance point in space. RF energy harvesting is a bit of a hot topic, there are a number of modules on the market atm. Just search for it on mouser or farnell to get started. Thanks btw for that LED schematic, so simple. I'm currently tuning a harvester around a BQ25504 and super caps. I'll give it a test next week. http://uk.mouser.com/Embedded-Solutions/Energy-Harvesting-Modules/_/N-8t3zx?P=1yzotr6 http://uk.mouser.com/Embedded-Solutions/Energy-Harvesting-Mo... This one contains other energy sources as well: http://uk.farnell.com/jsp/search/browse.jsp?N=2002+225290&Ntk=gensearch&Ntt=energy+harvesting&Ntx=mode+matchallpartial http://uk.farnell.com/jsp/search/browse.jsp?N=2002+225290&Nt...