Cellular telephones

Sohd tantalum capacitors have a high volumetric capacitance which makes them attractive for use in miniaturized electronic systems like cellular telephones, hand-held video cameras, and personal computers. The insensitivity of their capacitance to temperature and their abiUty to operate at temperature extremes explains why these devices are used in such harsh environments as automobile engine compartments. Sohd tantalum capacitors are extremely rehable and, therefore, are often the capacitor of choice in critical appHcations like spacecraft electronics, pacemakers, and safety equipment. 

Optoelectronic devices are found in numerous consumer products such as television, compact-disk players, laser communications, laser printers, radar detectors, cellular telephones, direct-broad-cast television, and many others. Many of these applications were developed in Japan and that country is still prominent in the field. 

Because electrical lines may be knocked out by emergency events, it is recommended that one or more cellular telephones be maintained in each of the facilities identified in Table 6.1 to be able to call for help and communicate with family members. Communicating with rescue workers and family during an emergency event will help minimize some of the psychological effects that may be experienced. Each building should also maintain one or more battery-powered AM/FM or short-wave radios and several sets of replacement batteries. The radios can be used to obtain updated reports on emergency response efforts and other useful information. 

Cellular telephone base stations Radio towers Microwave towers Lasers (including laser pointers)... 

In 1990, Sanyo and Matsushita initiated large-scale commercialization of small sealed nickel-metal hydride batteries. They are now joined by Dur-acell, Toshiba and Varta in a consortium which is known as the 3C alliance (camcorders, cellular telephones and computers). Several plants have been commissioned which are each producing 100-200 million cells per annum. It is forecast that nickel-metal hydride may overtake nickel-cadmium before the end of the century. In addition to the 3Cs nickel-metal hydride cells are used for a wide variety of cordless consumer products, communications equipment and other high rate long cycle life applications. 

Ultralife Batteries Inc. has recently announced the development of their Rechargeable Solid State System based on this technology. A schematic drawing of the cell is shown in Fig. 7.41. Single cells and battery packs are now in production. Energy densities in the ranges 100-125 Wh/kg and 200-300 Wh/dm3, as well as cyclability up to 1200 deep cycles, have been reported. Excellent characteristics are claimed. Cellular telephones, portable computers and camcorders appear to be the most suitable outlets for these PLI batteries. 

Much has happened in the world of batteries since the preface to the first edition was written almost 15 years ago. Some of the developments were predicted at that time, some were not. Perhaps the most important factor, which has led both to a renaissance in new developments and to a significant growth in demand, has been the phenomenal expansion in microelectronics-based, high value consumer products which need secondary cells with excellent energy density, good charge retention and other demanding electrical characteristics. The three Cs - cellular telephones, portable computers and camcorders - typify such applications. 

The small size of cellular telephones results from the use of sophisticated gallium arsenide (GaAs) semiconductors instead of ordinary silicon-based semiconductors. 

In the last 20 years, we have benefited from tremendous changes in telecommunication. The relatively simple change to portable phones enabled us to roam around the house while chatting, unlimited by the length of the cord that attaches the receiver to the base of the telephone, while the beeper and the cellular telephone allow us to talk to anyone around the world at any time. New cellular technologies also allow people to send text messages and check e-mail from a handheld cell phone. 

Improved telecommunication technology is not the only technology that has made our lives easier. Written communication is also instantaneous. We can send an e-mail or message instantly to someone not only from a computer, but also from a cellular telephone. Or perhaps you have a piece of writing or a form that must be sent but cannot be conveniently sent via the computer. Facsimile (fax) technology has also made sending the written word faster and easier. The document is transmitted to the receiver at once—it s almost like handing the copy to the recipient. 

With the widespread use of laptop computers, cellular telephones, and other portable electrical devices, the need for high energy density power sources has increased. In the past decade, two systems for these purposes have been commercialized nickel-metal hydride and lithium-ion batteries. For automotive applications, the interest in... 

Computers, TV sets, audio equipment, cellular telephones, and, obviously, the electronic components inside them, continue to shrink in size. Nothing dates a movie from the 1990s quite as much as seeing someone holding an old cell phone. One of the factors that allows smaller consumer products is thinner yet stronger materials. 

In many states of the United States they make it again the law for talking while driving with cellular telephone. In my opinion, is this a good idea I believe. 

For to many accidents, are happening with the cellular telephone, the driver he don t see (what happens) ahead. This terrible for every one especial the ones they getting hurt. Some accident really very terrible and, everyone going to the hospital. This should be the law. 

Li-ion rechargeables are presently finding widespread utility in portable electronic devices such as laptop computers, camcorders and cellular telephones. 

Ni-Cd batteries are extensively utilized in cordless power tools (cellular telephones, portable computers, toys, and so on), in electric vehicles, and for emergency and starting power. They have excellent performance both at low and high temperature and high cycle life. CdS is an important yellow pigment, with other compounds (CdSe in particular) it gives... 

Spikes in chromatograms can come from many sources, such as aging detector lamps or bubbles in the flow cell both can be easily corrected. External electrical noise sources, such as ovens, refrigerators, cellular telephones, and fluorescent lights, and other possible noise sources such as system electronics or from external electronic sources, and laboratory power feed may be beyond a chromatographer s control. 

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