Under Electronics (study of the control of electrons) all operations in control, control and amplifier circuits as well as the operations in this used components are understood. As a control variable a variable voltage or a variable current is here again an electric current without going through electromagnetism or a mechanically actuated control or switch. Optoelectronics is a branch of electronics and deals with the control of, as well as of light.
The concept electronics is derived from the Greek word elektron ( ήλεκτρον ), which means amber. Electronics is a portmanteau word that was derived from the words electron together ( the elementary ) and technology. The electronics were, the electron technique.
1873 Willoughby Smith discovered that selenium is able to pass in the light ( photoelectric effect ). In this way knowledge discovered Karl Ferdinand Braun in 1874 the rectifier effect. Stoney and Helmholtz coined the term of the electron as a carrier of electric current. 1883 Thomas Edison received a patent on a DC voltage regulator, which was based on the thermionic emission ( Richardson the Edison effect), a prerequisite for all vacuum tubes. 1897 began the development of the Braun tube by Karl Ferdinand Braun. In 1899, then began developing the top diode. 1904 John Ambrose Fleming gained a patent on a vacuum diode.
- History of the electron tube
At the beginning of the 20th century, the development of electron tubes was already well advanced. The first electron tubes have been developed and used already in electrical circuits. With the triode for the first time was a useful component for the construction of amplifiers available. This inventions such as radio, television and radar were possible.
In 1948 the first transistor was presented. Transistors such as tube as an amplifier, electronic switch, or can be used as an oscillator. However, transistors can be as opposed to vacuum tubes that need a lot of space and electrical power, produce very small, because they are based on semiconductor technology, making much higher current densities are possible.
In the 1960s, the production of complete, from a plurality of transistors and other components existing circuits succeeded on a single silicon crystal. The thereby introduced technology of integrated circuits ( IC short of Engl. Integrated circuit) has since led to a steady miniaturization. Today, the semiconductor electronics is the most important branch of electronics. As a key technology for the future polytronics is seen occasionally. It involves the merging plastic -based system functions for the vision of "intelligent plastic".
The analog technology is mainly concerned with the processing of continuous signals. Case, use is made of the physical laws which describe the behavior of components (resistors, capacitors, transistors, tubes, etc.) or you manage by circuit principles favorable conditions. Typical basic circuits are current sources, current mirrors, differential amplifiers and cascades, and reference elements such as the bandgap. This can be complicated circuits to build, such as amplifiers, with the help of which other functions can be constructed ( oscillator, filter, etc.). The operational amplifier is an amplifier having a differential input ( differential amplifier ). Its name comes from the fact that can be performed on it, mathematical operations ( subtraction, addition, integration, etc.). Operational amplifiers are widely used in analog electronics. The accuracy of the signal processing in the analog electronics by the manufacturing tolerances of the components and the non-idealities (such as noise, non-linearity, hysteresis ) and set by other disturbing effects such as crosstalk and coupling of interfering signals limits. There were very developed advanced methods that compensate for or minimize such errors, and thus allow accuracies in the range of 0.1 % to 0.001 %. Such high accuracy is required, for example to implement analog to digital converter with 20 bit resolution.
The digital electronics and digital technology is concerned (expressed as numbers or logical values) to the processing of discrete signals. The discretization always relates in the range of values and often also the temporal behavior. In practice, one is limited to bivalent systems, ie: voltages or currents are - apart from transients - only two values ( on / off, 1 or 0, and high / low, short H / L). The change in the values can take place at discrete time systems only at certain, generally equidistant instants which predetermines a clock. In digital electronics, analog signals are either prior to processing by means of analog-to- digital converters are digitized ( converted into digital signals ) or already exist in advance as discrete values. Transistors are used in the digital technique, as a rule as a switching amplifier, and not as an analog amplifier.
The advantage of digital electronics lies in the fact that following the digitization mentioned in the analog electronics disturbing effects no longer play a role, but at the cost of the component costs. For example, if an analog circuit subject to a maximum error of 0.1 %, this error can from about 10 -bit data width being undercut by digital circuits. An analog multiplier requires about 20 transistors, a digital multiplier with the same accuracy more than 20 times the number. The effort is growing by the digitization therefore first on, but this is more than compensated by the ever promoted miniaturization. Today can be applied to an integrated circuit, a very large amount of transistors realize (the number is typically in the 10 million ). The advantage now is that, for example, the voltage level can vary to a considerable extent without impeding the correct interpretation as 1 or 0. Thus, it is possible that the components of the integrated circuits may be very inaccurate, which in turn allows further miniaturization. The characteristics of the circuit are thus largely decoupled from the physical properties of the components.
The simplified description of digital circuits with the two states H and L do not always enough, especially at faster speeds and higher frequencies to characterize them or to design. In the limit of the circuit is the majority of the time in the transition between the two logically defined states. Therefore, analog and high-frequency technical aspects must be considered in such cases often increasingly. Even on slow circuits, there can be problems that can only be understood by analog perspectives; an example is the problem of metastability of flip-flops.
Logic of digital electronics
Digital circuits - also called switching systems or logic circuits - consist mainly of simple logic elements such as AND, NAND, NOR, OR, NOT gates and components with which digital signals can be stored, such as flip-flops or counters. Each of these logical functions can be achieved by working in the so-called switch mode electronic components ( eg transistors). The integration of these circuits on a chip ( monolithic circuit ) creates complex electronic components such as microprocessors.
The high-frequency electronic or high frequency technology which focuses on the production and broadcasting, and the receipt and processing of electromagnetic waves. Applications thereof are, for example, the wireless technology with radio, television, radar, remote control, wireless telephony, navigation as well as the avoidance of unwanted oscillations ( interference, EMC) and uncontrolled radiation ( shielding). Other areas of high-frequency electronics, microwave technology, wired transmission of information or areas of medical electronics. The transition from the low-frequency to high-frequency technique is fluid.
Power electronics refers to the branch of electrical engineering, which has the conversion of electric energy with electronic components to the task. The conversion of electric power transformers or rotating machine sets is not expected to go against power electronics.
Important components are electron tube, Integrated circuits, semiconductor diode, zener diode, transistor, thyristor, resistor, capacitor and inductor. From a scientific point of view, in the last three not to arrangements that comprise or utilize electrical effects, classical electrodynamics is quite enough here. But as they are often built and sold with the actual electronic components, has nevertheless generally enforced in practice this assignment.
This is called passive components when the primary resistors, capacitors and inductors are meant. Among the active components usually are understood all types of integrated circuits, semiconductor devices and electronic tubes.
All these devices are offered in a wide variety of types. The exact mapping of the logically calculated working together electronic components on a circuit board, an electronic circuit is formed.
An independent and logically working arithmetic operator chip is the modern processor, which can be found not only on the motherboard of a computer, but is a part of modern industrial and automotive technology.
The electronics now includes countless areas of semiconductor electronics on quantum electronics to nanoelectronics. Since the advent of the computer, the continuous development of information technology and the increasing automation, the importance of electronics has continuously expanded. The electronics in our society today takes an important place and has become indispensable in many areas.
In 2007, 38% of all electronic products produced in the world came from the Asia - Pacific region. In 1995 this proportion was 20%. China alone increased its share from 3% in 1995 to 16 % in 2007. Among the top 10 countries are also South Korea, Malaysia, Singapore and Thailand. The share of Western Europe in 2007 was 19% of global production (equivalent to about 192 billion euros ). In the performance order of the size of the electronics manufacturing in Western Europe following ranking prevails (as of 2006): Germany, France, Great Britain, Ireland, Italy.