Power Electronics

Data Points

Piezoelectric Energy Harvester Generates 40 µW

Energy-harvesting devices are of great value for applications in which batteries cannot be replaced easily. A typical example is a network of autonomous sensors that are spread over a large area or placed in locations that are difficult to access. Vibration harvesters, in general, make use of electromagnetic, electrostatic or piezoelectric conversion to generate electrical power. IMEC, the Belgian research center in nanoelectronics and nanotechnology, and its sister company IMEC-NL have developed, modeled and characterized a miniaturized vibration harvester based on a piezoelectric transducer.

For an input vibration with a resonance frequency of 1.8 kHz and an amplitude of 180 nm, a maximum experimental output power of 40 µW was measured. This is well in range with the amount of power needed by wireless-sensor applications, such as the pulse-oxymeter developed earlier by IMEC and IMEC-NL, operating from the Holst Centre in Eindhoven, The Netherlands.

“After the demonstration of a battery-less pulse-oxymeter, which is fully powered by a thermal scavenger, this is another encouraging result which brings us closer to seeing miniaturized scavengers in real-life applications,” says Bert Gyselinckx, program director for IMEC-NL. “We believe that the first of such devices will see market introduction in five years and will become mainstream by the end of the next decade.”

The device consists of a piezoelectric capacitor formed by a platinum electrode, a PZT layer and a top aluminum electrode. The capacitor is fabricated on a cantilever that supports a mass on its tip. As the harvester is subjected to oscillations, the mass causes the piezoelectric layer to be stretched. By doing so, it generates electrical power that can drive a small load.

A model has been developed to estimate the output power for specific designs that use this concept. Using the model, the output power of devices can be maximized by optimizing the quality factor Q through low-parasitic dissipation, as well as the generalized electromechanical coupling (GEMC) factor through improved coupling between the electrical and mechanical parts of the device.

For additional information, visit www.imec.be and www.holstcentre.com.

Demand for Energy Efficiency Drives Growth of Advanced Lighting

The Freedonia Group predicts that U.S. demand for advanced lighting products will rise nearly 14% per year through 2011, reaching $4.4 billion. The Cleveland-based market research firm explains that this increase will be fueled by consumer desires for more energy-efficient lighting, which will boost demand for compact fluorescent lamps (CFLs). By 2011, CFLs are expected to replace incandescents as the dominant choice in residential building applications, according to the firm.

Meanwhile, development of improved light-emitting diode (LED) technology will create opportunities for LED products in lighting applications. Already gaining share in the motor vehicle market, LEDs pose a longer-term threat to CFLs in building applications. These and other trends are presented in The Freedonia Group's new study, “Advanced Lighting.”

Although U.S. demand for advanced lighting will be robust, growth in domestic production will be modest, according to the firm. It forecasts that shipments of advanced lighting products will rise less than 2% annually through 2011, reaching $1.6 billion. The United States is a net importer of advanced lighting products. The Freedonia Group predicts that this trade deficit will widen as imports continue to expand faster than both overall demand and exports through 2011.

For more information contact Corinne Gangloff at 440-684-9600 or [email protected].

Vendors Collaborate to Power and Cool Data Centers

Emerson Network Power and Sun Microsystems have announced a joint-development effort focused on defining and developing a high-efficiency power and cooling infrastructure for high-performance computing (HPC) data centers. This initiative will enable the Sun Blade 6000 and Sun Blade 8000 server platforms to be deployed with no impact on data-center cooling.

A key enabler of this initiative is a Liebert Blade Thermal Assessment, which is designed specifically to assist Sun customers in deploying their Sun Blade servers. As part of an introductory offer, Emerson will offer an on-site assessment at no charge for up to 5000 sq ft of data-center space with an existing or planned Sun Blade Scalable Unit for HPC system.

The two organizations also will collaborate on a joint program validating Liebert cooling solutions' ability to eliminate the impact of heat dissipation from the Sun Blade 6000 and Sun Blade 8000 modular system platforms. In addition, these companies will work together on the continued deployment of Liebert XD cooling systems in Sun engineering labs, which create HPC environments for testing and development of power and cooling technologies with future generations of Sun servers.

Study Finds Delta Still Tops in Power-Supply Industry

According to a market study by IMS Research, Delta Electronics maintained its lead among power-supply vendors in 2006, despite continued consolidation within the industry. The study, which ranked vendors by dollar market share, also found that Astec/Emerson and Lite-On Technology held their 2005 positions as number two and three, respectively. However, mergers and differences in market performance affected the rankings of a few of the top 10 merchants, as the worldwide market for power supplies grew from approximately 13.9 billion in 2005 to $15.8 billion in 2006 (see the table).

One of the vendors whose ranking changed was Lambda. According to David Dewan, market analyst for power and energy at IMS Research, Lambda moved up to 4th place as a result of its merger with TDK. Meanwhile, a new spot in the top 10 opened up as a result of the takeover of Artesyn by Emerson, and FRIWO jumped from 10th to 6th as a result of an “excellent year,” says Dewan. “AcBel had flat revenues in 2006, which has seen them leapfrogged by fellow Taiwanese power-supply manufacturer HIPRO (part of the Chicony Group) and move from 6th to 9th.”

“The continued consolidation within the power-supply industry has highlighted the importance of becoming a large global player to compete effectively,” says Dewan. “The Eltek Energy and Valere Power tie-up is a good example of combining regional strengths to create a worldwide player.”

IMS also notes that the wave of power-supply industry consolidation continued with the recent announcement by C&D Technologies that it has completed the sale its power electronics division to Murata Manufacturing. According to IMS, this report also clearly indicates the strength of the Taiwanese companies within the power-supply industry.

Five of the 10 companies are Taiwanese, with two of these in the top three. This dominance has come from strong demand from the consumer and computer sectors, which require large numbers of power adapters, and the growth in demand for increasingly large flat-panel televisions.

For more information, see www.imsresearch.com.

1. Delta Electronics
2. Emerson
3. Lite-On Technology
4. TDK Lambda
5. Tyco Electronics
7. Phihong
9. AcBel Polytech
10. Sanken Electric

Power-supply vendor rankings in 2006 by revenue. (Table courtesy of IMS Research.)

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