Power Electronics

Data Points

Wearable Electronics System Creates Power Challenge

A venture between Motorola and Burton, known as Audex, has led to the development of a line of jackets that provides musical entertainment and wireless connectivity for snow boarders. The power design for the system, which includes a Bluetooth-enabled handset interfaced with an iPod MP3 player, was a major engineering challenge.

According to Dave Hess, engineering manager for the modules group within Motorola's Mobile Me group, the greatest engineering challenge was the power design of the system due to its low-temperature operating environment. Specifically, the concern was to maintain the heat and, therefore, the power output of the Li-ion battery contained within the Power Pod module. This module fits within the Chest module of the system, which contains the audio circuits and wireless electronics, and is secured by a special pocket within the jacket.

The other components of the jacket are the Control module (accessed on the left sleeve), the Microphone module (placed in the chest) and the speakers (placed in the collar). With the exception of the display, wall adapter and battery, all of the components within the jacket were re-engineered. For example, the speakers and microphone are equipped with a special water-resistant fabric from SaatiTech.

According to Hess, the approximate power budget of the overall system is as follows: 45% for the keypad and display backlight; 45% for the speaker drivers; 5% for the Bluetooth radio; and 5% for the remaining functions.

For more information, see http://burton.motorola.com/.

UPS Market Rises in 2006

The global uninterruptible power-supply (UPS) market grew by 11.5% in the first half of 2006, according to the latest data from IMS Research (Wellingborough, U.K.), a market research and consulting company. Strong growth was observed in all three major regions when compared to the same period in 2005.

The Europe, Middle East and Africa (EMEA) region recorded the highest growth for the first half of the year, with the Americas and Asia following close behind. “EMEA is the smallest UPS market and is typically associated with low-moderate growth — compared to Asia Pac and the Americas — as this region is more dependent upon the industrial sectors and less dependent upon more volatile sectors like datacom,” noted Ash Sharma, senior market analyst with IMS Research's Power & Energy group. “In the last few years, highest growth has been seen in Asia Pac followed by the Americas.”

All three regions boasted double-digit growth figures, according to IMS Research. The results are revealed in the company's latest analysis of the UPS market, which provides up-to-date measurements of market performance. While the company is still analyzing the data, it initially believes the growth is being “driven by the datacom sector and, to some extent, the SOHO sector. Underlying this is an increasing awareness of the importance of power quality and protection,” Sharma explained.

For further information, see www.imsresearch.com.

Battery Defects Linked to Manufacturing

Recent reports of Li-ion battery fires in laptop computers have prompted recalls of the Sony-built batteries by Dell (issued on Aug. 15) and Apple (issued on Aug. 24). The companies have made statements as to what went wrong with the batteries in these incidents and what action has been taken to ensure the safety of mobile computer batteries in the future.

In an Aug. 22 statement posted on the Direct2Dell website, Dell's Vice President of Engineering Forrest Norrod noted that Dell has taken several measures to ensure battery safety in its systems. This includes the use of safety features such as charge-current limiting, as well as observing physical design safety criteria such as those outlined in the IEEE 1625 standard. While these features improve the safety of batteries, Norrod says that they do not prevent or correct the type of manufacturing defects that were responsible for the recently documented battery fires in Dell notebook computers.

The defect that led to the latest recalls by Dell and Apple relates to battery contamination during the manufacturing process. Specifically, particles of metal became embedded within critical areas inside the affected Li-ion cells. Under certain circumstances, these particles could eventually create an internal short circuit that would cause excessive localized heating. The resulting mixture of heat and released oxygen can lead to a fire in the battery.

According to Norrod, the solution is two-fold. First, certifications must be established for ensuring that battery-manufacturing processes are free of contamination. Second, the individual components of the battery must be designed to shield the critical areas of the battery from possible contamination during manufacturing.

Norrod added that Sony has implemented changes to the manufacturing process that produced the defective batteries, and that Dell is now satisfied these changes have resolved the safety issues in Sony's Li-ion batteries.

IPC Accelerates Li-Ion Battery Standardization

The IPC - Association Connecting Electronics Industries is fast-tracking its development of standards for the manufacture of Li-ion batteries for portable and handheld electronics. The group's announcement came only a day after Dell reported that it was recalling certain Li-ion batteries. Standardization of these batteries had already been a goal of the IPC's OEM Critical Components Committee, which includes representatives from Dell, Lenovo and other major computer manufacturers, but now the issue has been brought to the forefront. The committee is meeting this month to begin the process of developing standards.

“The committee started discussing the need for a battery standard about two months ago. I think the Dell recall [drives] home the need for developing these standards and may spur more companies to participate,” observed Kim Sterling, IPC's vice president of marketing and communications.

“Without a doubt, standardization can and will address the issue of operation and safety called into question by the use of lithium-ion batteries,” noted John Grosso, chairman of the OEM Critical Components Committee and director of supplier engineering and quality, sub-tier and critical components at Dell. Grosso said that the committee plans to identify current standards related to Li-ion batteries with the goal of standardizing design, performance and safety requirements for these batteries.

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