The History of Electrical Engineering

 

Article by Prof. Dr. Walter Kaiser (former Chair of Historical Development of Technology)

Elektromagnetischer Zeigertelegraph Siemens-Pressebild Electromagnetic pointer telegraph by Werner Siemens, 1847; implemented by Johann Georg Halske

Roughly between 1790 and 1830, in physics the basics of electrodynamics- so called by Ampère - were discovered. Since 1820, there have also been initial approaches to a theoretical description. Amazingly fast - and in the 19th Century only comparable to chemistry - industrial electrical engineering developed on the basis of these new physical discoveries. Initialized by sophisticated optical telegraphs on the one hand and limited by the weak electrochemical power sources on the other, the focus of this early electrical engineering clearly was on telegraphy. Government users, i.e., military and administration, as well as wealthy individuals and corporations, however, were enabled to convey messages over great distances with unprecedented speed.

  “Zentrale“ der Deutschen Edison-Gesellschaft Bildrechte beim SiemensForum, München “Head office“ of the German Edison Society in Berlin (1885), used for illuminating the royal theater, the German Reichsbank, and some renowned restaurants. (Equipment by Siemens)

"Power Engineering" followed in the second stage of the development of industrial electrical engineering, booming from 1880 onwards. Due to improved large generators which became independent of permanent magnets, electro-forming, electric motors, and lighting systems where able to finally enforce themselves. While arc lamps filled streets and squares with bright light, the incandescent bulb allowed electric lighting inside buildings. The achievements of electrical engineering became visible to the public not least through the construction of tramways since 1880.

  Electric tramway Bildrechte beim SiemensForum, München The first electric tramway operating on schedule in Lichterfelde/Berlin, Siemens 1881

Around 1900, the area of industrial electrical engineering was already extraordinarily diverse: in Germany, the companies Siemens and AEG competed, in Hungary there was Ganz & Co., in Switzerland Brown, Boveri & Cie. Electrical engineering in the United States was dominated by the internationally growing foundations of Edison, Westinghouse and Thomson and simultaneously shaped by the violent clashes in the transmission systems, i.e., the contrast between direct current and alternating current. As a medium of the electrical engineering industry and stage for the presentation of important innovations served the major international electrical engineering exhibitions. With the exhibition in Frankfurt in 1891, the three-phase AC current transmission system which dominates Central Europe until today, became available. Almost simultaneously with the onset of the boom in power engineering and in close interaction with industry, the new engineering discipline of electrical engineering was created in a number of German technical universities .

A signal of the growing economic importance of electrical engineering and also of a lasting change in production was the use of phase current and three phase motors in heavy industry from about 1910 onwards. The electrification of the individual life was rather slow, however. For example, electric lighting had to prevail against the cheaper gas light. Despite early patents, electrical equipment found its way into private households in large numbers only from the 1920s and 1930s onwards.

  Photo: Bosch First refrigerator from Bosch, spring exhibition Leipzig 1933

"Weak current technology" had first developed world-embracing telegraph and telephone networks, with considerable sums having been invested in devices, switching systems, transmission lines and cables. It was not until around 1910 that it experienced its second heyday in the form of wireless communications technology. What is fascinating is that even with the simple transmitter and receiver technology of the early years, the Atlantic could be bridged. This development accelerated at the end of World War I and in between the two wars, with the general broadcast and early television technologies being in the foreground. Before the outbreak of World War II, however, especially radio broadcasting had become a major economic factor, the central medium, and an integral part of family life.

  Radio at the water sports field Siemenswerder an der Havel, around 1928 Bildrechte beim SiemensForum, München Radio at the water sports field Siemenswerder an der Havel, around 1928

Even more than in World War I, communications technology was advanced in World War II, from radar technology to the first approaches to digital transmission and switching. These approaches led - in densely populated areas - in the 1960s and - nationwide - at the end of the 1970s to the establishment of digital networks integrating services in communications technology. The result was initially a modernization of transmission and switching in the telephone systems.

 

Since 1990, however, the cumbersome car telephone, which is only reserved for a few users, has developed into digital mobile radio, which is now widespread worldwide and is characterised by huge numbers of subscribers. These developments were made possible by the development of information theory and innovations in hardware, i.e. the simultaneous increase in the availability of microelectronic components. The development of microelectronics since the discovery of the transistor effect (1947) and since the development of early integrated circuits (1960 to 1970) had long since led to enormous changes in computer technology, for example in mainframes for main research and industry, but since 1980 above all also in the private sphere through the establishment of the personal computer. New industrial giants appeared on the market, according to the IBM group founded in the USA.

  Fully transistorized digital computer Siemens 2002, Hannover Messe 1959, then RWTH Aachen University Siemens-Pressebild Fully transistorized digital computer Siemens 2002, Hannover Messe 1959, then RWTH Aachen University

But the impact of microelectronics basically covered all sectors of technology, from numerically controlled machine tools and automotive electronics, particularly those promoted by Bosch, to imaging processes in medical engineering. After the highly developed television, phono and radio technology had remained astonishingly long on the level of analogue technology since 1960, the compact disc developed by Philips and Sony also led to the implementation of digital processes in consumer electronics since 1980.

 

Around 1990, a whole new dimension of private and industrial use of modern information and communication technologies finally opened up the World Wide Web. In addition to the e-mail service, it was only one possible use of the older Internet. However, a new era in the processing of knowledge began in 1998 with the search engine of the market leader Google Inc. operating on the data stock of the World Wide Web, which increasingly displaces classical literature searches. In addition, the technical importance of the Internet is also increasing, in the form of cloud computing, or generally in the relocation of computing power and storage capacity into the network. At the same time, the commercial, social and political implications of the Internet exceed all the opportunities and risks that information technology and communication technology have created so far.

  Compact Disc Digital Audio System, introduced 1982/1983 by Sony and Philips, here Philips CD-Player CD100 from 1983 Bildrechte bei Philips Communications Compact Disc Digital Audio System, introduced 1982/1983 by Sony and Philips, here Philips CD-Player CD100 from 1983

The dramatic increases in performance in information and communication technology over the last 40 years, already apparent from today's perspective, will probably hardly reach a development plateau, or even come to a halt. Things will continue to go more or less steeply uphill, although not only fired by advances in hardware, but also by work on the architecture of the systems. However, the changes that have already taken place and the growth rates still to be expected must not distort the view of the potentially existential problem of electrical engineering, namely the medium- and longer-term supply of energy. In this respect, generators, transformers, high-voltage lines and switches as well as computer-supported transmission and distribution systems have by no means become classic areas. They too have inevitably retained the status of high technology. A spectacular feature are the high-voltage direct current transmission lines based on modern power electronics, which have allowed low-loss electricity transport between large hydroelectric power plants and distant population centres since 1975 and which today also connect offshore wind power plants to the grids on the mainland. It is therefore to be expected that information and communication technologies will further improve their performance in terms of data rates and transmission quality in the future. Conversely, however, energy technology is likely to set the tough conditions for future growth.

  First high-voltage direct current (HVDC) transmission with thyristors from Mozambique hydroelectric power station to South Africa, 1975 Bildrechte bei SiemensForum, München First high-voltage direct current (HVDC) transmission with thyristors from Mozambique hydroelectric power station to South Africa, 1975