{"id":730,"date":"2007-04-03T00:10:19","date_gmt":"2007-04-03T00:10:19","guid":{"rendered":"https:\/\/www.docbug.com\/blog\/archives\/730"},"modified":"2007-04-03T00:10:19","modified_gmt":"2007-04-03T00:10:19","slug":"wireless-power","status":"publish","type":"post","link":"https:\/\/www.docbug.com\/blog\/archives\/730","title":{"rendered":"Wireless power"},"content":{"rendered":"<p><a href=\"http:\/\/www.pat2pdf.org\/pat2pdf\/foo.pl?number=7027311\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/docbug.com\/blog\/wp-content\/uploads\/legacy\/powercast-patent-fig.png\" border=\"1\" height=\"306\" width=\"287\" alt=\"powercast-patent-fig.png\" align=\"right\" \/><\/a>  <\/p>\n<p><a href=\"http:\/\/www.powercastco.com\/\">Powercast<\/a> (formerly Firefly Power Technologies, and spin-off based on <a href=\"http:\/\/etd.library.pitt.edu\/ETD\/available\/etd-07212004-192328\/\">University of Pittsburgh research<\/a>) made a splash at CES this year with their dime-sized receiver that harvests RF energy from a nearby wall-wart transmitter. Based on their <a href=\"http:\/\/www.pat2pdf.org\/pat2pdf\/foo.pl?number=7027311\">patent<\/a> and <a href=\"http:\/\/www.google.com\/patents?vid=USPAT6856291\">related<\/a> <a href=\"http:\/\/www.google.com\/patents?vid=USPAT6289237\">tech<\/a> <a href=\"http:\/\/www.google.com\/patents?vid=USPAT7057514\">from<\/a> <a href=\"http:\/\/www.google.com\/patents?vid=USPAT7084605\">PITT<\/a>, the technology looks pretty darned simple (so simple I&#8217;m surprised there&#8217;s not prior art, but then this isn&#8217;t my field). It&#8217;s basically just an antenna with a bunch of taps, each tap consisting of an inductor to resonate with the desired RF frequency and a rectifying diode to turn the energy into DC. That DC voltage is integrated across a series of capacitors, and stored in another capacitor.<\/p>\n<p>I&#8217;ve not seen any detailed specs on how efficiency drops off with range from the transmitter, though <a href=\"http:\/\/money.cnn.com\/magazines\/business2\/business2_archive\/2007\/04\/01\/8403349\/index.htm?postversion=2007033007\">a Businesses 2.0 write-up<\/a> claims their range is only about 3 feet, with voltages too small for laptops but good enough for small devices. Their tech has also been tested for <a href=\"http:\/\/www.sensormgmt.com\/Articles\/Powered%20By%20FireFly60614.pdf\">recharging wireless sensors<\/a> at the Pittsburgh Zoo, and Philips is apparently coming out with a wirelessly-powered lightstick using the technology later this year.<\/p>\n","protected":false},"excerpt":{"rendered":"<p><a href=\"http:\/\/www.pat2pdf.org\/pat2pdf\/foo.pl?number=7027311\"><img loading=\"lazy\" decoding=\"async\" src=\"http:\/\/docbug.com\/blog\/wp-content\/uploads\/legacy\/powercast-patent-fig.png\" border=\"1\" height=\"306\" width=\"287\" alt=\"powercast-patent-fig.png\" align=\"right\" \/><\/a>  <\/p>\n<p><a href=\"http:\/\/www.powercastco.com\/\">Powercast<\/a> (formerly Firefly Power Technologies, and spin-off based on <a href=\"http:\/\/etd.library.pitt.edu\/ETD\/available\/etd-07212004-192328\/\">University of Pittsburgh research<\/a>) made a splash at CES this year with their dime-sized receiver that harvests RF energy from a nearby wall-wart transmitter. Based on their <a href=\"http:\/\/www.pat2pdf.org\/pat2pdf\/foo.pl?number=7027311\">patent<\/a> and <a href=\"http:\/\/www.google.com\/patents?vid=USPAT6856291\">related<\/a> <a href=\"http:\/\/www.google.com\/patents?vid=USPAT6289237\">tech<\/a> <a href=\"http:\/\/www.google.com\/patents?vid=USPAT7057514\">from<\/a> <a href=\"http:\/\/www.google.com\/patents?vid=USPAT7084605\">PITT<\/a>, the technology looks pretty darned simple (so simple I&#8217;m surprised there&#8217;s not prior art, but then this isn&#8217;t my field). It&#8217;s basically just an antenna with a bunch of taps, each tap consisting of an inductor to resonate with the desired RF frequency and a rectifying diode to turn the energy into DC. That DC voltage is integrated across a series of capacitors, and stored in another capacitor.<\/p>\n<p>I&#8217;ve not seen any detailed specs on how efficiency drops off with range from the transmitter, though <a href=\"http:\/\/money.cnn.com\/magazines\/business2\/business2_archive\/2007\/04\/01\/8403349\/index.htm?postversion=2007033007\">a Businesses 2.0 write-up<\/a> claims their range is only about 3 feet, with voltages too small for laptops but good enough for small devices. Their tech has also been tested for <a href=\"http:\/\/www.sensormgmt.com\/Articles\/Powered%20By%20FireFly60614.pdf\">recharging wireless sensors<\/a> at the Pittsburgh Zoo, and Philips is apparently coming out with a wirelessly-powered lightstick using the technology later this year.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[14],"tags":[],"class_list":["post-730","post","type-post","status-publish","format-standard","hentry","category-wearable-computing"],"_links":{"self":[{"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/posts\/730","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/comments?post=730"}],"version-history":[{"count":0,"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/posts\/730\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/media?parent=730"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/categories?post=730"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.docbug.com\/blog\/wp-json\/wp\/v2\/tags?post=730"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}