World's first semiconductor rectifier and the transistor is, when no power semiconductor or microelectronics semiconductor division. In 1958, China began the first research topic Thyristor (originally known as PNPN device). In similar time, the study of integrated circuits began gradually. From semiconductor devices to the two direction. The former became the basis for power electronics, while the latter led to the development and micro-electronics and information electronics.
According to the system, power system devices are classified to the machinery, integrated circuits, electronic systems are included. As the semiconductor leader in the electronic systems, coupled with the semiconductor integrated circuits is the main body, which after a long-term evolution of integrated circuits in a number of occasions, has become almost synonymous with semiconductor devices only.
At the end of the sixties and early seventies, the country has set off a "SCR" hot. The boom continued a long time, great influence, and therefore still believe that the domestic power of semiconductors is the main SCR. The late seventies, the development of a thyristor family. And called the name of a standardized "thyristor." As the technology to regulate the power switch, so the wear and tear on a small device, so as the energy trump card. Its application is to cover all fields. China was first mooted in 1979, the establishment of Power Electronics Society, IEEE slightly earlier than the establishment of the United States Institute of Power Electronics (Power Electronics Society). Power Electronics Society of China was founded, as a result of the importance of professional development is very rapid. However, because the focal point was the relationship, it does not like the United States become an independent professional institutes, and was subsequently set up part of the China Electrotechnical Society.
The translation and definition of Power Electronics for Power Electronics (the original idea was also known as the Power Electronics), and the popularity of power electronics played a role. Mechanical, electrical, electronic and other departments are very concerned about its development. Related to the power semiconductor devices has also been known as the power electronic devices. However, this name is very difficult to find abroad, but the corresponding terms. "Electricity" in reference to electronic access to universal, but also left a number of sequels. People mistakenly believe that only high-power direction is the "power" of the main electronic devices, and the difficulty of the rapid development of the MOSFET as a "power electronics" of the other main. From that point, I would like to use power semiconductor devices as the subject of this article, and power electronic devices can be used to express a broader sense to include other non-semiconductor, including a variety of power electronic devices.
The development of power semiconductor devices in three stages
The development of power semiconductor devices can be divided into three stages. The first stage is 60 to the seventies, when the various types of thyristors and power transistors Darlington significant development, or what might be called the era of bipolar. Its clients are mainly for industrial applications, including power systems, such as locomotive traction. The second stage is 80 to the nineties, due to the rise of the power MOSFET to power electronics into a new area. Modern 4C booming industry: the Communication, Computer, Consumer, Car (communication, computer, consumer electronics, automobiles) to provide a new vitality. Before and after the twenty-first century, the development of power semiconductor devices have entered the third phase, that is, and integrated circuit combined with a growing stage, Figure 1 and Figure II made to the above description of a simple sum. Of course, first of all need to focus on that here is this: when the continuous development of power semiconductor devices, the previous stage has not been the dominant product from the stage of history. For example, SCR is still an important product. China has in recent years the introduction of ultra-high-power thyristor, thyristor-controlled technology, such as China's major power transmission project, providing a key device. Recently, in considering the introduction of IGCT technology. In this regard it should be said that has gradually moved towards the world. This is our country going on the many major infrastructure. Although the view from the United States, the production of high-power thyristors have been less and less on the economic development of the two countries are not identical. I draw in Figure 2 in power semiconductor devices in both directions in the development. The left side of the bipolar nature of the direction toward the integration of ultra-high-power and direction. The right direction is unipolar, it is more established and integrated circuits of the inseparable relationship between closely.
虽然音响设备对于轿车来讲，只是一种辅助性设备，对车子的运行性能没有影响。但随着人们对享受的要求越来越高，汽车制造商也日益重视起轿车的音响设备，并将它做为评价轿车舒适性的依据之一。轿车音响的发展史也是电子技术的发展史，电子技术的每项重大的技术进步都推动着轿车音响的发展。早在1923年美国首先出现了装配无线电收音机的轿车，随后许多轿车都步其后尘，在仪表板总成上安装了无线电收音机。这时候车用无线电收音机都是用电子管，直到50年代出现半导体技术后，轿车收音机出现了技术革命，用半导体管逐步取替了电子管，提高了轿车收音机的寿命。70年代初，卡式收录机进入了市场，一种可播放卡式录音带的车用收放两用机出现在轿车上，同时机芯开始应用集成电路。直至80年代末，一般轿车的音响多以一个卡式收放两用机与一对扬声器为基础组合，扬声器分左右两路声道，有的置于仪表板总成的两侧，有的置于车门，有的置于后座的后方，收放两用机输出功率多在20瓦左右。
今天，轿车音响又进入了一个新的里程，向大功率多路输出、多喇叭环回音响、多喋式镭射CD等方向发展。世界音响制造商也将轿车音响辟为一个专门的工业部门，针对轿车的特殊环境，充分考虑车厢的音响效果，采用高新技术制造轿车音响设备，其播送的音响效果完全能与家用音响相媲美。日本凌志LS400型轿车的AM/FM音响系统就有5个放大器，配有7个分频喇叭，包括2个拱形高频喇叭，4个宽频带喇叭和一个后装式8寸低频喇叭，使整个车厢充满了立体音的环回感受。
市面上已经有各种供轿车专用的高级音响设备，一些汽车音响爱好者将大功率放大器和电子网络器安置在轿车行李箱内，将超低音大口径喇叭和其它型号喇叭分别嵌入后窗下围板和车门板上，使用独立的直流电源，功率输出达上百瓦以上，音色浑厚优美，高低有错，把车厢内狭小的空间变成了令人愉快的音乐欣赏室，予人以美的享受。
汽车的运行环境是十分恶劣的，包括振动、高温、噪音、电磁波等都会干扰车内电子设备的正常工作，因此轿车专用的音响设备不论从设计和工艺制造方面的要求都要比家用音响严格，而且价格不菲，从这个意义上讲，高性能的轿车音响实际上是当今音响世界中的顶级品。
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