RF-Powered Wireless Sensors

AutomationWorld has published an article on energy harvesting technologies demonstrated at the 2009 Sensors Expo, including information on Powercast.

Energy Harvesting Advances
http://www.automationworld.com/news-5664

“While vibration energy harvesting may be most common for industrial applications, a different approach was being shown by Pittsburgh-based Powercast Corp. (www.powercastco.com). At its Sensors Expo show booth, the company was demonstrating its Powercaster transmitter, which was beaming a radio frequency (RF) signal toward the company’s Powerharvester receivers mounted in other nearby booths. The receivers were harvesting energy from the RF field and converting it to DC power sufficient to operate low-power sensor devices. Harry Ostaffe, Powercast director of marketing, said the company has so far deployed the technology in custom projects for military and industrial clients, with typical transmission distances “in the 10s of feet” using a three-watt transmitter.”

Power was transmitted to booths for Esensors and Infinite Power Solutions and converted back to DC with the P2100 Powerharvester.  The Esensors wireless sensor was located about 35 feet from the Powercast transmitter.  It was connected to a Powercast Yagi antenna module and was activated about every 90 seconds.  The IPS energy cell was connected to a Powercast sleeve dipole antenna module and was pulse charged at about 25 feet.  Longer charge distances were possible for both devices, but they were mounted for display purposes.