Market trends in the electronics industry

The statistical survey of the electronics industry in the United States, published annually by the Electronic Industries Association, for several years has shown a trend of importance to all IEEE members whose employment and job assignments depend on the markets for electronic systems, equipment, and components. That trend is a decrease in the year-to-year growth of factory sales in two major components of the industry: products sold to the government and to the consuming public. The other major component, sales of industrial products, has shared this trend of arrested growth, but there is an encouraging turnaround that is evident in the projected figures for 1969. Although product sales are by no means the only significant economic factor in these industries, this indicator has a fundamental influence on future product design and development. The statistics reviewed in this article are taken by permission from the recently published ``EIA Yearbook ? 1969.' This 94-page document1 contains detailed data on sales of individual product lines, funding, employment, and related industry statistics. It is recommended highly to IEEE members, in the U.S. and elsewhere, who have an interest in the economic underpinning of our profession.     

Recent advances in power electronics

Recent advances in several key areas of power electronics technology, such as power semiconductor devices, power converter circuits, and control of power electronics, are discussed. The structure and characteristics of IGBT, SIT, SITH, and MCT devices are reviewed. The principal converter types and their recent trends are described. A brief review of power integrated circuits is included. The features of microcomputer and VLSI control are described, and recent advances in microcomputers are highlighted. The principles of expert systems, fuzzy control, and neural networks are presented     

Switched-capacitor power electronics circuits

One of the main orientations in power electronics in the last decade has been the development of switching-mode converters without inductors and transformers. Light weight, small size and high power density are the result of using only switches and capacitors in the power stage of these converters. Thus, they serve as ideal power supplies for mobile electronic systems (e.g. cellular phones, personal digital assistants, and so forth). Switched-capacitor (SC) converters, with their large voltage conversion ratio, promise to be a response to such challenges of the 21st century as high-efficiency converters with low EMI emissions and the ability to realize steep step-down of the voltage (to 3 V or even a smaller supply voltage for integrated circuits) or steep step-up of the voltage for automotive industry or Internet services in the telecom industry. This paper is a tutorial of the main results in SC-converter research and design     

Automotive electronics power up

People are spending increasing amounts of time in their cars. As a result, automakers are equipping vehicles with more and more power-draining creature comforts as selling points. Cup holders have given way to navigational systems, separate driver and passenger climate controls, and surround sound and compact disk players. But performance and handling improvements under the hood, such as dynamic stability controls, electronic suspensions, and precision-controlled fuel injection, also need power from the 14-V system featured in today's cars. To handle the situation, automotive manufacturers and suppliers are embracing a 42-V standard for system voltage as they design new products. The challenge for designers, however, is that the cost of the new electronics cannot prohibit the economic production of automobiles. This hurdle must be cleared before cars with 42-V systems will become available to consumers. The paper discusses why 42 Volts was chosen, how many batteries will be needed, control systems, start/stop operation, and the influence of silicon devices on cost     

Recessed-gate structure approach toward normally off high-Voltage AlGaN/GaN HEMT for power electronics applications

A recessed-gate structure has been studied with a view to realizing normally off operation of high-voltage AlGaN/GaN high-electron mobility transistors (HEMTs) for power electronics applications. The recessed-gate structure is very attractive for realizing normally off high-voltage AlGaN/GaN HEMTs because the gate threshold voltage can be controlled by the etching depth of the recess without significant increase in on-resistance characteristics. With this structure the threshold voltage can be increased with the reduction of two-dimensional electron gas (2DEG) density only under the gate electrode without reduction of 2DEG density in the other channel regions such as the channel between drain and gate. The threshold-voltage increase was experimentally demonstrated. The threshold voltage of fabricated recessed-gate device increased to -0.14 V while the threshold voltage without the recessed-gate structure was about -4 V. The specific on-resistance of the device was maintained as low as 4 m/spl Omega//spl middot/cm/sup 2/ and the breakdown voltage was 435 V. The on-resistance and the breakdown voltage tradeoff characteristics were the same as those of normally on devices. From the viewpoint of device design, the on-resistance for the normally off device was modeled using the relationship between the AlGaN layer thickness under the gate electrode and the 2DEG density. It is found that the MIS gate structure and the recess etching without the offset region between recess edge and gate electrode will further improve the on-resistance. The simulation results show the possibility of the on-resistance below 1 m/spl Omega//spl middot/cm/sup 2/ for normally off AlGaN/GaN HEMTs operating at several hundred volts with threshold voltage up to +1 V.     

High-voltage DC transmission: a power electronics workhorse

Thyristor-based HVDC converter technology is used for highly reliable power transfer across natural or national boundaries or between AC systems designed for different frequencies or incompatible frequency controls. The author discusses the benefits of HVDC transmission and describes HVDC transmission system configurations. The author then describes the use of thyristors in HVDC converters     

台湾电子信息产业迈向新世纪——产品阴晴不同，企业预作筹谋

笔记本电脑市况趋缓荣景难再 据美国市场调查公司ＩＤＣ的资料显示,去年全球笔记本电脑的出货量为２４２２万台,比前年成长２１．５％,预计今年将成长１４．６％,达２７７７万台。台湾六大笔记本电脑厂商,包括广达、宏基、仁宝、英业达、华宇及大众自己的估算,去年台湾出货量约１２００万台,今年因景气难以捉摸,预计在１５５０－１７００万台之间,成长３０－４０％。台“资策会”预估,从２００２年起笔记本电脑全球增长率将开始低于１０％,在这高度成熟的市场环境里,对企业的经营实力将是一番考验。 台式机重点转向获利 ２００…     

无电池电子设备的驱动方法

双层电容器技术的最新发展已使它能够代替特定二次电力存储应用中的再充电电池(参考文献1)。电容器提供了相对于再充电电池的明显优势,其中包括实际无限次数的充电/放电周期、短路情况下的生存能力、只需要过压保护的简单充电     

Capacitive components for power electronics

As the consumer and industrial requirements for compact, high-power density electrical power systems grow substantially over the next decade, development of high power/energy density capacitor technology is a major enabling technology component element. For microsecond to fractional-second electrical energy storage, discharge, filtering, and power conditioning, capacitor technology is unequalled in flexibility and adaptability to meet a broad range of requirements in the future     

The evolution of power electronics

Distinctive attributes of power electronics equipment are high power capability, controllability and static switching to meet the goals of high efficiency and high dependability. Aspects of the early history of power electronics are traced from magnetic amplifiers, thyratrons, and ignitrons to power semiconductors     

A project-oriented power electronics laboratory

This paper presents a power electronics educational laboratory suitable for undergraduate and graduate students. The pedagogical approach taken is one where the students revisit previously studied material placed in a practical context. This approach supports the prerequisite lecture material and allows study of some practical issues which are best handled in a laboratory setting. The course format makes the students gradually more responsible for the design of control circuitry which permits nominal operation of generic power converters. The laboratory experience culminates in a project where the student analyzes, designs, simulates and demonstrates a power electronics related topic     

Batteries for low power electronics

Progress in battery technology is closely tied to that in electronics, however, it is slow in comparison. Growth in new systems once in production, is also slow, depending upon the development of new devices which need their performance characteristics. This has been true, in particular for lithium cells operating at 3 V. Older electrochemical systems such as C-Zn, alkaline, Zn-air, NiCd, and lead-acid continue to get better, and maintain the market for devices which can use them. Primary lithium batteries are growing in use as new devices are designed around their higher voltage and superior shelf life. The Li-MnO₂ system dominates the commercial marker. At least 16 manufacturers produce many sizes and configurations from high rate “D” cells to 50 mAh thin, flat cells. Two new secondary (rechargeable) systems, nickel-metal hydride and lithium ion, have recently been introduced They are growing at a rapid rate in response to environmental concerns and the need for higher energy density. Other secondary systems such as Zn-air and lithium-polymer electrolyte are nearing commercial production. Environmental regulations continue to impact battery use and disposal, leading to more interest in secondary systems which can be reused many times before disposal. Mercury has largely been banned from use in primary batteries, both as a corrosion inhibitor for zinc and as a cathode in the mercuric oxide cell. Existing and emerging battery systems are discussed in terms of energy content, shelf and cycle life and other characteristics     

The state-of-the-art of power electronics in Japan

Since the late 1950s, power electronics has been developing by leaps and bounds without saturation to become the key technology essential to modern society and human life as well as to electrical engineering. This paper mainly focuses on the state-of-the-art of power electronics technology and its medium to high-power applications because the author cannot survey the whole spectrum of power electronics ranging from a 5 W switching regulator to a 2.8 GW high-voltage DC transmission system now under construction in Japan. This paper also presents prospects and directions of power electronics in the 21st Century, including the personal views and expectations of the author     

Technology 1993-industrial electronics

Notable advances during 1992 are reviewed. They include improved precision in computerized numerical control (CNC) for machine tools; easier, high-level programming for programmable logic controllers; faster and more efficient machine vision; reduced false accept and reject ratios in X-ray laminography for the examination of solder joints, particularly in surface-mounted boards; and high-wattage power electronic devices. The latter offer lower voltage drop when turned on, plus the ability to control motors and other manufacturing equipment with a virtually unity power factor on utility lines     

Technology 1992-industrial electronics

Important trends and events are highlighted. The use of fuzzy logic expanded. The use of programmable logic controllers in distributed control made headway. Low-cost vision systems were introduced, as were faster X-ray laminography systems. Growing emphasis on keeping humans who work around robots safe was evident. More robust motion and speed controls for both robots and motors became available     

Technology 1992-medical electronics

Advances of note during 1991 are reviewed. A microprocessor-based fiber-optic sensing system that monitors blood gas in real time was introduced. Also introduced was a tympanic or ear thermometer that measures infrared heat generated by the eardrum and surrounding tissue and displays the temperature in about 2 s. Interest in artificial heart research was reviewed. Images of the human brain as it performed the simple task of recalling a word showed that the recall process was going on in unexpected parts of the brain, not just in the hippocampus     

Technology 1993-consumer electronics

The adoption of a US ghost-canceling reference signal by the Advanced Television Systems Committee was one of the significant events during 1992. Other noteworthy developments were the adoption of a broad regulatory framework for introducing HDTV by the US Federal Communications Commission and the preparation worldwide for digital audio broadcasting (DAB). Home theater began to make inroads with consumers, the competition for recordable digital audio heated up, a bill to regulate cable television prices was passed by the US Congress, and video telephone was introduced