Problems on Capacitors & Direct Current Circuits

http://www.esnips.com/web/Physics3

Problems used in former tests about Capacitors & Direct Current Circuits.
[Download the file PruebaFisica3_CapacitanciaCircuitos.pdf]

Physics 3-06. The Electric Field II

Physics 3-06. The Electric Field I

Building a Better Battery

http://www.wired.com/wired/archive/14.11/battery.html

By John Hockenberry
They run out of juice – or burst into flames – at exactly the wrong time. Can't anyone make a battery that doesn't suck?
Issue 14.11 - November 2006

3M's Safer, Lithium-Ion Batteries

http://www.technologyreview.com/read_article.aspx?id=17653&ch=energy

By Kevin Bullis

New electrodes and electrolytes could mean higher energy and less danger from lithium-ion batteries. 

Wednesday, October 25, 2006

A Practical Fuel-Cell Power Plant

http://www.technologyreview.com/read_article.aspx?id=17644&ch=energy

By David Talbot



GE's advance allows for a solid-oxide fuel cell to use coal-based fuels at costs approaching that of conventional power plants.

Monday, October 23, 2006

Printing Fuel Cells

http://www.technologyreview.com/read_article.aspx?id=17626&ch=energy

By Kevin Bullis 

A new printing process could cheaply make complex fuel-cell reformers, and other microscale devices.

Tuesday, October 17, 2006

Safer, Higher-Capacity Batteries

http://www.technologyreview.com/read_article.aspx?id=17603&ch=energy

By Kevin Bullis 

Silver-zinc battery chemistry could replace lithium ion in laptops and other electronics--if such batteries can be made cheaply enough.

Wednesday, October 11, 2006

Assessing GM's Fuel Cell Strategy

http://www.technologyreview.com/read_article.aspx?id=17586&ch=energy

By Kevin Bullis

The automaker plans to begin rolling out a test fleet of fuel-cell cars, but some experts say it's a mistake.

Friday, October 06, 2006

Will Silicon Light Illuminate the Future?

http://www.technologyreview.com/read_article.aspx?id=17588&ch=energy

By Tyler Hamilton

A startup says it can make silicon-based lighting that will compete with conventional incandescent bulbs and existing LED-based lighting. 

Friday, October 06, 2006

More Efficient Solar Cells

 http://www.technologyreview.com/read_article.aspx?id=17577&ch=energy

By Prachi Patel-Predd

A semiconductor material with three energy bands uses more sunlight, by trapping low-energy photons.

Wednesday, October 04, 2006

Powerful Batteries That Assemble Themselves

http://www.technologyreview.com/read_article.aspx?id=17553&ch=energy

By Kevin Bullis

MIT researchers are developing low-cost manufacturing methods based on the rapid reproduction of viruses. Angela Belcher explains.

Thursday, September 28, 2006

Virus-Assembled Batteries

http://www.technologyreview.com/read_article.aspx?id=16673&ch=biztech&sc=&pg=1

By Kevin Bullis

A biological template ramps up electrode performance and scales down size.

Images courtesy of Angela Belcher, MIT.Copyright Technology Review 2006

Recipe for using viruses to make an electrode:

Dip a polymer electrolyte in a solution of genetically engineered viruses.

These form a uniform coating on the electrolyte.

Dip the coated polymer into a solution of battery materials.

The viruses coat themselves with the battery material, transforming into nanowires with a regular crystal structure good for high-energy batteries.

Friday, April 07, 2006

Special Report: Facing Global Warming

http://www.technologyreview.com/special/oil/index.aspx









Readily available energy technologies could be put in use today to forestall global warming. Technology Review examines some of these technologies and argues that they require not further refinement but a considered, long-term deployment strategy.

BMW's Hydrogen Hopes

http://www.technologyreview.com/read_article.aspx?id=17526&ch=energy

By David Talbot

Hydrogen may never be feasible as a fuel for vehicles, but BMW is pushing ahead anyway with an advanced hydrogen-gas combustion hybrid.

The internal combustion engine in BMW’s new hydrogen-gasoline hybrid engine can switch seamlessly between the two fuels. And control systems optimize the concentrations of hydrogen being burned, which can minimize or eliminate one of the downsides of hydrogen combustion: the formation of nitrogen oxides. While BMW hopes its new model will help drive the adoption of hydrogen in vehicles, experts are skeptical. (Credit: BMW)

Friday, September 22, 2006

Lithium Ion Hybrid Batteries

http://www.hybridcars.com/lithium-ion-hybrid-batteries.html

A Laptop in Every Garage
The emergence of small lightweight long-running lithium-ion batteries has helped create a market for notebook computers, cell phones, and other portable devices from the iPod to the BlackBerry. Now, efforts to scale that technology for use in car batteries could do for the automotive industry what it did for computer and phone companies. The benefit for consumers could be revolutionary: hybrid or pure electric cars with great efficiency, acceleration and range—at the same price or cheaper than today's conventional cars.

Ultracapacitors & Hybrid Electric Vehicles

http://maxwell.com/ultracapacitors/applications/transportation.html

Application: Hybrid Electric Vehicles (HEV)

Key Customer Requirements

Manufacturers of HEV's are looking at relieving battery's load during high power times, such as initial acceleration and braking. These are the instances when the batteries see the highest current levels. By load leveling these spikes the batteries will last longer, saving the customer money.

Maxwell Solution

Maxwell Technologies ultracapacitors were designed to work with system batteries to improve power management and relieve peak load times stress on batteries. Our ultracapacitor technology protects the battery. It allows the battery to handle the energy requirements while the caps handle the high power requirements.

Customer Benefits

Ultracapacitors significantly improved power management in the hybrid electric vehicles and extended battery life. In addition, ultracapacitors allow for lower emissions, better fuel-efficiency and advanced electrical drive capabilities. The new power system using ultracapacitors allowed the HEV to recapture and reuse braking energy. Compared to conventional diesel engines: reduction of fuel consumption was estimated at greater than 50%; reduction in particulate emissions was greater than 90%; and reduction of nitrogen oxide emissions was 50%.

Ultracapacitors & Medical Applications

http://maxwell.com/ultracapacitors/applications/medical.html

Application
High reliability Medical equipment that requires Medical grade electrical isolation, conditioned and/or backup power.

Key Customer Requirements
Reliable distribution of Medical grade conditioned power to Medical Imaging, Diagnostic and Treatment equipment that requires high reliability and availability. Power systems that integrate seamlessly with the entire system and provide power protection and conditioning for worldwide voltages and frequencies.

Maxwell Solution
POWERCACHE® System can be engineered to provide worldwide industry leading noise suppression, Medical grade voltage regulation and transformation along with custom power distribution.

Customer Benefits
Power engineering expertise that can help develop and integrate power systems seamlessly into their entire system. Increased reliability and continued operation of their systems.

Ultracapacitors & Space

http://maxwell.com/ultracapacitors/applications/space.html

Application: Satellites

Customer Requirements

Satellites require efficient power solutions. As with any other system that uses power, satellites have a need for reliable and efficient power delivery. In addition, satellites often require large busts of power to perform processor-intensive operations, which may be for a limited amount of time. Or, during a power outage it is often critical to maintain some electrical functions, such as the memory contents, that may require a small amount of current.

Maxwell's Solution

The high reliability of BOOSTCAP ultracapacitors makes them an ideal solution for mission critical electronics that must operate consistently, even during power outages. Although originally designed for terrestrial power needs, recent studies of Maxwell's ultracapacitors show that their performance remains the same when subjected to the unique environment of space. The PC5 has survived the environmental tests for MIL-STD-810 while our PC10, PC100 and PC1000 ultracapacitors continued to perform within spec while being exposed to gamma doses up to 200 Krad(Si).

Customer Benefits

Based on the results of these studies, BOOSTCAP® ultracapacitors are a viable option for power needs in low earth orbit satellite applications and pending further testing, may also be suitable for deep space missions. The smaller size and weight of BOOSTCAP ultracapacitors, as compared to traditional batteries and other power packs of similar performance, allows for a greater packaging efficiency which is essential for satellite applications.

These capacitors are used in the International Space Station PEEK (Portable Electrical Equipment Kit). The PEEK hardware provides electrical power extension cables and outlets as well as 120 to 28Vdc converter units to power portable electrical hardware on the ISS.

Evaluation of Maxwell Technologies PC-5 Ultracapacitor, by The Parts Analysis and Assurance group at the Johnson Space Center:

http://maxwell.com/ultracapacitors/support/papers/PC5_evaluation.html

http://maxwell.com/ultracapacitors/support/papers/PC5_evaluation.pdf

Ultracapacitors & Entertainment

http://maxwell.com/ultracapacitors/applications/toys.html

Application: Battery Operated Toys

Customer Requirements

Price is key in this industry. Toy companies will explore every option to reduce expenses and increase their overall margins. After price, the toy manufacture business requirements include product availability and performance.

Maxwell Solution

Maxwell Technologies PC5 and PC10 cells both have the performance and footprint characteristics to be applied in capacitor toys. The toy market has embraced the use of ultracapacitor technology. Toy manufactures can benefit by placing a permanent ultracapacitor on board in place of a battery. A clear advantage is the capacitor is much lighter which awards performance advantages. It can be re-charged hundreds of times by a battery pack.

Customer Benefits

Our small cells are a flat design that provides the designer with a new option for developing a toy application. The use of ultracapacitor technology also has more energy per gram than other solutions available on the market. This provides our toy designers with more run time.