Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Smaller, lighter power adaptors take the weight off laptops

17.12.2003


As notebook computers become thinner and lighter, the ever-present bulky power adapters used for line current approach the weight of the laptops, but smaller and lighter adapters may be on the way, thanks to piezoelectric technology, according to a Penn State electrical engineer.



"Electromagnetic transformers are shrinking slightly, but there are theoretical limitations in reducing the general size," says Dr. Kenji Uchino, professor of electrical engineering. "A piezoelectric motor and transformer can be much smaller and lighter."

Transformers are needed to convert the 115-volt, 60-cycle power available from a standard U.S. wall receptacle to the 13 to 14 volts direct current used by laptops.


"Eventually we would like to make it the size of a pen, but that is far away," says Uchino. "When we can do that, the adapter will be a component of the laptop, not attached to the cord as a separate piece. Right now, we can reduce the adapters to one-fourth of their current size."

Uchino notes that while his group targets the laptop or notebook computer market, these smaller adapters are suitable for any appliance that requires an ac to dc converter and transformer.

Reporting in The Proceedings of the 5th International Conference on Intelligent Materials, Uchino, who heads the International Center for Actuators and Transducers at Penn State; T. Ezaki, Taiheiyo Cement Corporation, Japan; and A. Vazquez Carazo, Face Electronics, described their piezoelectric transformer.

Piezoelectric material moves when under an electric voltage, and, when displaced by outside pressure, these materials produce an electric voltage.

Transformers are made from piezoelectric materials by applying a chopped electric voltage to one side of a piezoelectric wafer. This on and off voltage creates a vibration in the material, which is converted to an ac voltage on the other side of the wafer. The amount of increase or decrease in the voltage transformed is dependent on the gap between the electrodes.

Most laptops require about 15 volts direct current with less than one amp of current and about 12 watts of power. By manipulating the length and width of the piezoelectric chip, the researchers can convert 115 volts to 15 volts. A rectifier then converts the alternating current to direct current.

The original piezoelectric devices were rectangular, but they could not produce sufficient power, so the researchers switched to a circular configuration.

"Smaller, less complex piezoelectric devices are already in use as step up transformers in some laptops to light the monitors which can take 700 volts to turn on and 50 to 150 volts to continue their operations," says Uchino.

One advantage of piezoelectric PC power adapters is that they do not produce the heat that conventional electromagnetic transformers produce. Electromagnetic power adapters not only produce heat, but also noise and interference. Piezoelectric power adapters operate in the ultrasonic range so humans cannot hear any sound produced and they do not produce electromagnetic interference.

"These power adapters were developed for the American and Japanese market where the line voltage is 100 to 125volts and 50 to 60 cycles," says Uchino. "Eventually, we also developed power adapters that convert 220 volts and 50 cycles so they can be used in the European market."

Other devices that could use these smaller, lighter power converters include printers, CD and DVD players, tape recorders and other appliances that operate on both battery and wall plugs.

The piezoelectric PC power adapter was developed at Penn State in collaboration with Face Electronics of Virginia and Taiheiyo Cement Corporation, Japan. Taiheiyo is planning to mass-produce the devices in 2004.

A’ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu/

More articles from Power and Electrical Engineering:

nachricht Waste from paper and pulp industry supplies raw material for development of new redox flow batteries
12.10.2017 | Johannes Gutenberg-Universität Mainz

nachricht Low-cost battery from waste graphite
11.10.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>