Electronics deals with electrical circuits that involve active components such as vacuum tubes, transistors, diodes, integrated circuits, optoelectronics, and sensors, associated Passivity (engineering), and interconnection technologies. Commonly, electronic devices contain circuitry consisting primarily or exclusively of active semiconductors supplemented with passive elements; such a circuit is described as an electronic circuit.
The nonlinear behaviour of active components and their ability to control electron flows makes amplification of weak signals possible. Electronics is widely used in information processing, telecommunication, and signal processing. The ability of electronic devices to act as switches makes digital information-processing possible. Interconnection technologies such as circuit boards, electronics packaging technology, and other varied forms of communication infrastructure complete circuit functionality and transform the mixed components into a regular working system.
Electricity and Electromechanics science and technology deals with the generation, distribution, switching, storage, and conversion of electrical energy to and from other energy forms (using wires, Electric motor, Electric generators, Battery (electricity), switches, relays, transformers, resistors, and other passive components). This distinction started around 1906 with the invention by Lee De Forest of the triode, which made electrical Amplifier of weak radio signals and audio signals possible with a non-mechanical device. Until 1950 this field was called "radio technology" because its principal application was the design and theory of radio transmitters, Receiver (radio), and vacuum tubes.
most electronic devices use semiconductor components to perform electron control. The study of semiconductor devices and related technology is considered a branch of solid-state physics, whereas the design and construction of electronic circuits to solve practical problems come under electronics engineering. This article focuses on engineering aspects of electronics.
Vacuum tubes (Thermionic valves) were among the earliest electronic components.
Digital circuits are electric circuits based on a number of discrete voltage levels. Digital circuits are the most common physical representation of Boolean logic, and are the basis of all digital computers. To most engineers, the terms "digital circuit", "digital system" and "logic" are interchangeable in the context of digital circuits.
Most digital circuits use a binary system with two voltage levels labeled "0" and "1". Often logic "0" will be a lower voltage and referred to as "Low" while logic "1" is referred to as "High". However, some systems use the reverse definition ("0" is "High") or are current based. Quite often the logic designer may reverse these definitions from one circuit to the next as he sees fit to facilitate his design. The definition of the levels as "0" or "1" is arbitrary.
Ternary computer (with three states) logic has been studied, and some prototype computers made.
Computers, electronic quartz clock, and programmable logic controllers (used to control industrial processes) are constructed of Digital data circuits. Digital signal processors are another example.
Highly integrated devices:
Mathematical methods are integral to the study of electronics. To become proficient in electronics it is also necessary to become proficient in the mathematics of circuit analysis.
Circuit analysis is the study of methods of solving generally linear systems for unknown variables such as the voltage at a certain Node (circuits) or the current through a certain Path (graph theory) of a Graph (discrete mathematics). A common analytical tool for this is the SPICE circuit simulator.
Also important to electronics is the study and understanding of electromagnetic field theory.
Due to the complex nature of electronics theory, laboratory experimentation is an important part of the development of electronic devices. These experiments are used to test or verify the engineer’s design and detect errors. Historically, electronics labs have consisted of electronics devices and equipment located in a physical space, although in more recent years the trend has been towards electronics lab simulation software, such as CircuitLogix, Multisim, and PSpice.
Today's electronics engineers have the ability to Circuit design Electronic circuit using premanufactured building blocks such as power supply, semiconductors (i.e. semiconductor devices, such as transistors), and integrated circuits. Electronic design automation software programs include schematic capture programs and printed circuit board design programs. Popular names in the EDA software world are NI Multisim, Cadence (ORCAD), EAGLE (program) PCB and Schematic, Mentor (PADS PCB and LOGIC Schematic), Altium (Protel), LabCentre Electronics (Proteus), gEDA, KiCad and many others.