Powercast and CAP-XX Team on Battery-Free Power Supply for Wireless Sensors

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Press Release

Powercast and CAP-XX Team on Battery-Free Power Supply for Wireless Sensors
Powercast RF energy harvester & supercapacitor reference design presented at nanoPower Forum

San Jose, Calif. – May 18, 2009 – Darnell nanoPower Forum – Today, engineers from Powercast and CAP-XX Limited (LSE:CPX) will introduce a wireless power module reference design combining Powercast’s RF energy-harvesting technology with a CAP-XX supercapacitor to create a perpetual, battery-free power source for wireless sensors commonly used in environmental monitoring, building automation, industrial controls and other condition-monitoring systems.

Low-power energy harvesting can supply the average power required by many sensor-based systems, but cannot provide the peak power needed to collect and transmit data over wireless networks such as IEEE 802.15.4 (Zigbee), 802.11 (WLAN) or GSM/GPRS. This is the industry’s first reference design using commercial components that harvests RF energy from low-power radio waves, stores it in a supercapacitor, and then delivers high power bursts when charged.

The wireless power module reference design integrates a power receiving antenna, a Powercast PowerharvesterTM receiver, and a CAP-XX supercapacitor for energy storage and peak transmission power. Low-power wireless sensors or RF modules can be added with simple “two-wire” integration. The module measures approximately eight inches tall, one inch wide and ¼ inch thick at the body (http://www.cap-xx.com/rethink/news/photogallery.htm#BritePower).

In operation, the design creates a perpetual power supply for fixed or mobile wireless sensor nodes, such as those located throughout a building, eliminating the need for batteries or wired power. Powercast’s PowercasterTM transmitter, which powers this reference design, sends radio waves to the Powerharvester integrated into the module. The Powerharvester converts energy received from these radio waves into DC power, trickle-charges the supercapacitor, and then delivers power from the supercapacitor to the wireless sensor. This cycle repeats as the module receives additional radio waves, which can be sent continuously, on-demand or on a scheduled basis. This design uses the 915 MHz band, but can be adapted for other frequencies, or set to harvest environmental radio waves from TV, radio or mobile phone networks.

The Powercaster transmitter provides controllable, 24 x 7 wireless power, allowing wireless sensors to avoid using potentially unreliable ambient types of energy harvesting such as solar or heat.

CAP-XX vice president of applications engineering, Pierre Mars, and Powercast head of technology platforms, Charlie Greene, will present their collaborative paper, “Harvesting RF Energy and Powering a Wireless Sensor Node Using a Supercapacitor,” in the energy harvesting session on Monday, May 18 at the Darnell nanoPower Forum in San Jose, California.

“This ‘fit and forget’ self-generating power source guarantees that sensors deployed throughout a building or local area will receive power without batteries or potentially unreliable environmentally-harvested energy such as solar or heat,” said Mars.

“Wireless sensor networks are increasingly popular, but today are predominantly powered by disposable batteries,” explained Harry Ostaffe, director of marketing for Powercast. “The RF energy harvester and supercapacitor combination eliminates the cost and hassle of replacing and disposing of batteries, and enables wireless sensor networks to scale to thousands of nodes with minimal maintenance.”

About CAP-XX:
Sydney, Australia-based CAP-XX is a world leader in thin, flat supercapacitors for space-constrained electronic devices. Supercapacitors resolve the performance limitations of batteries and other current-limited power supplies, and provide backup power if the primary power source fails.

CAP-XX supercapacitors enable manufacturers to make smaller, thinner, longer-running and more feature-rich devices such as camera phones, solid state drives, handheld PCs and battery-free condition-monitoring systems using the company’s BritePowerTM architectures. The company is listed on the Alternative Investment Market (AIM) in London. For more information, visit http://www.cap-xx.com or email sales@cap-xx.com.

About Powercast: (www.www.powercastco.com)
Powercast Corporation is a leading innovator of wireless power technology. Founded in 2003, Powercast’s proprietary core technology and related intellectual property pioneered the model for completely untethered electronic devices by transmitting and harvesting common radio waves similar to those in wireless communications. Emerging applications include wireless sensors, advanced displays, novelty lighting and other low-power electronic devices. Contributing to a greener world, Powercast’s technologies eliminate or reduce the need for batteries, extend sensor networks into hard-to-service locations and enable greater energy efficiency for HVAC, lighting and other systems.

Powercast Releases Additional Wireless Power Development Kits

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Press Release

Pittsburgh, PA – May 7, 2009 – Powercast, a leader in the commercialization of RF energy harvesting and wireless power solutions, announced it has released additional versions of its Lifetime Power Evaluation and Development Kit.  The new kits, available for purchase at www.www.powercastco.com, represent offerings focused more specifically for recharging Alkaline and Lithium Ion batteries.

Batteries are used in numerous small, portable, and mobile electronic devices.  Powercast’s technology enables these devices to use rechargeable batteries and be finally untethered™ from power cords or inconvenient, close proximity charging methods.  Disposable batteries and their adverse environmental impact can be eliminated from devices with Powercast’s RF energy harvesting and embedded wireless power solutions.

Powercast’s technology can provide constant charge, over distance, between one or more sources and multiple receivers. These devices can also be dormant, with zero stand-by power, and activated remotely with power being sent on-demand, on a scheduled basis, or continuously.

[ IDTechEx ] Includes Powercast in Article about RF Energy Harvesting

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Researchers at Intel, Seattle, have demonstrated harvesting RF power from a TV transmission tower to power a commercially available thermometer/hygrometer with LCD display. From a balcony at the Intel Research Laboratory in Seattle the researchers harvested RF power from the KING-TV tower at a distance of 4.1km using a standard television aerial. With the antenna manually pointed toward the transmission tower, the ambient RF harvesting system was then attached to the battery terminals of a commercially available indoor/outdoor temperature and humidity meter with an LCD display which is normally powered by a 1.5V AAA battery. The researchers found that the device function was normal using power harvested from the tower and that the display was as good as when the system was powered by a battery. The voltage was found to drop when the antenna was directed away from the tower.
With a different approach of deliberately sending out an interrogatory signal, Intel researchers have demonstrated the WISP (Wireless Identification and Sensing Platform). WISPs are not really energy harvesting because they do not employ preexisting ambient energy. They have the capabilities of RFID tags, but also support sensing and computing. Like any passive RFID tag, WISP is powered and read by a standard off-the-shelf RFID reader, harvesting the power it uses from the reader’s emitted radio signals. WISPs have been used to sense quantities such as light, temperature, acceleration, strain, liquid level, and to investigate embedded security. Intel predicts the next phase of WISP work will involve the interaction of many WISPs resulting in a new battery-free form of wireless sensor networking. With RFID technology, the tag and the tag reader have to be in very close proximity but with the technique described above the weather station can get its power from a TV antenna pointed at a local TV station antenna that is 4km away.
Powercast has also developed so called Powerharvester Modules which are high efficiency RF energy harvesting devices that convert received RF energy into DC power. Powercast is a radio frequency that is transmitted over a small area, and its energy is harvested wirelessly to power to small devices like cell phones. A feature of the receiver is that, while the transmitter is highly focused in the power range it broadcasts (either in the 900MHz or 2.4GHz bands); the receiver can pick up and convert any RF energy regardless of frequency. Batteries or other energy storage devices can be recharged in close proximity or remotely, or low power devices can be driven directly from the received power.
RF harvesting from ambient sources has great potential to impact on the cellular phone industry and the portable electronic device industry as a whole.