- Electronics
Electronics refers to the flow of charge (moving
electron s) throughnonmetal conductors (mainlysemiconductor s), whereas electrical refers to the flow of charge throughmetal conductors. For example, flow of charge throughsilicon , which is not a metal, would come under electronics; whereas flow of charge throughcopper , which is a metal, would come under electrical. This distinction started around1908 with the invention byLee De Forest of thetriode . Until1950 this field was called "Radio technics" because its principal application was the design and theory of radiotransmitter s and receivers.The study of new
semiconductor devices and related technology is considered a branch ofphysics whereas the design and construction ofelectronic circuit s to solve practical problems comes underelectronics engineering . This article focuses onengineering aspects of electronics.Electronic devices and components
An electronic component is any physical entity in an electronic system whose intention is to affect the electrons or their associated fields in a desired manner consistent with the intended function of the electronic system. Components are generally intended to be in mutual electromechanical contact, usually by being soldered to a
printed circuit board (PCB), to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Components may be packaged singly or in more complex groups as integrated circuits. Some common electronic components arecapacitor s,resistor s,diode s,transistor s etc.Types of circuits
Analog circuits
Most analog electronic appliances, such as
radio receivers, are constructed from combinations of a few types of basic circuits. Analog circuits use a continuous range of voltage as opposed to discrete levels as in digital circuits.The number of different analog circuits so far devised is huge, especially because a 'circuit' can be defined as anything from a single component, to systems containing thousands of components.
Analog circuits are sometimes called
linear circuit s although many non-linear effects are used in analog circuits such as mixers, modulators, etc. Good examples of analog circuits include vacuum tube and transistor amplifiers, operational amplifiers and oscillators.Some analog circuitry these days may use digital or even microprocessor techniques to improve upon the basic performance of the circuit. This type of circuit is usually called "mixed signal." Sometimes it may be difficult to differentiate between analog and digital circuits as they have elements of both linear and non-linear operation. An example is the comparator which takes in a continuous range of voltage but puts out only one of two levels as in a digital circuit. Similarly, an overdriven transistor amplifier can take on the characteristics of a controlled
switch having essentially two levels of output.Digital circuits
Digital circuits are electric circuits based on a number of discrete voltage levels. Digital circuits are the most common physical representation of Boolean algebra 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.In most cases the number of different states of a node is two, represented by two voltage levels labeled "Low"(0) and "High"(1). Often "Low" will be near zero volts and "High" will be at a higher level depending on the supply voltage in use.
Computer s, electronic clocks, andprogrammable logic controller s (used to control industrial processes) are constructed ofdigital circuits.Digital Signal Processor s are another example.Building-blocks:
*Logic gate s
* Adders
* Binary Multipliers
* Flip-Flops
*Counter s
* Registers
*Multiplexer s
*Schmitt trigger sHighly integrated devices:
*Microprocessor s
*Microcontroller s
*Application-specific integrated circuit (ASIC)
*Digital signal processor (DSP)
*Field-programmable gate array (FPGA)Heat dissipation and thermal management
Heat generated by electronic circuitry must be dissipated to prevent immediate failure and improve long term reliability. Techniques for heat dissipation can includeheatsink s and fans for air cooling, and other forms ofcomputer cooling such aswater cooling . These techniques useconvection , conduction, &radiation of heat energy.Noise
Noise is associated with all electronic circuits. Noise is defined [IEEE Dictionary of Electrical and Electronics Terms ISBN-13: 978-0471428060] as unwanted disturbances superposed on a useful signal that tend to obscure its information content. Noise is not the same as signal distortion caused by a circuit.
Electronics theory
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 or the current though a certain branch of a network. A common analytical tool for this is the
SPICE circuit simulator.Also important to electronics is the study and understanding of
electromagnetic field theory.Computer aided design (CAD)
Today's electronics engineers have the ability to design circuits using premanufactured building blocks such as power supplies,
semiconductor s (such astransistor s), andintegrated circuit s.Electronic design automation software programs includeschematic capture programs andprinted circuit board design programs. Popular names in the EDA software world areNI Multisim , Cadence (ORCAD ), Ea"gle PCB and Schematic, Mentor (PADS PCB and LOGIC Schematic), Altium (Protel), LabCentre Electronics (Proteus) and many others."Construction methods
Many different methods of connecting components have been used over the years. For instance, early electronics often used point to point wiring with components attached to wooden breadboards to construct circuits. Cordwood construction and
wire wrap s were other methods used. Most modern day electronics now useprinted circuit board s (made ofFR4 ), and highlyintegrated circuit s. Health and environmental concerns associated with electronics assembly have gained increased attention in recent years, especially for products destined to the European Union, with itsRestriction of Hazardous Substances Directive (RoHS) andWaste Electrical and Electronic Equipment Directive (WEEE), which went into force in July 2006.Electronics industry
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Semiconductor sales leaders by year Branch pages
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Analog electronics
*Circuit Design
*Digital electronics
*Fuzzy electronics
*Integrated circuit
*Microelectronics
*Optoelectronics
*Semiconductor
*Semiconductor device See also
*Analog signal processing
*Circuit diagram
*Computer engineering
*Datasheet
*Digital signal processing
*E-waste
*Electrical engineering
*Electronic circuit
*Electronic tuner
*Electronic Waste Recycling Fee
* IEEE - the Institute of Electrical and Electronics Engineers
*List of 4000 series integrated circuits
*List of 7400 series integrated circuits
*Mechatronics
*Signal theory
*Transducer References
2. The Art of Electronics ISBN-13: 978-0521370950
3. All New Electronics Self Teaching Guide ISBN-13: 978-0470289617
External links
* [http://www.capacitorx.com/capacitors/ Capacitor Types and Tutorial]
* [http://www.audiocircuits.wikidot.com Audio Circuits] - [http://www.circuits.wikidot.com Circuits1] - [http://www.freecircuits.wikidot.com
* [http://www.electroniq.net Electronics tutorials, projects and software] Circuits2]* [http://www.phy.davidson.edu/instrumentation/NEETS.htm Navy 1998 Navy Electricity and Electronics Training Series (NEETS)]
* DOE 1998 Electrical Science, Fundamentals Handbook, 4 vols.
** [http://hss.energy.gov/NuclearSafety/techstds/standard/hdbk1011/h1011v1.pdf Vol. 1, Basic Electrical Theory, Basic DC Theory]
** [http://hss.energy.gov/NuclearSafety/techstds/standard/hdbk1011/h1011v2.pdf Vol. 2, DC Circuits, Batteries, Generators, Motors]
** [http://hss.energy.gov/NuclearSafety/techstds/standard/hdbk1011/h1011v3.pdf Vol. 3, Basic AC Theory, Basic AC Reactive Components, Basic AC Power, Basic AC Generators]
** [http://hss.energy.gov/NuclearSafety/techstds/standard/hdbk1011/h1011v4.pdf Vol. 4, AC Motors, Transformers, Test Instruments & Measuring Devices, Electrical Distribution Systems]
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* [http://www.ibiblio.org/obp/electricCircuits/ Lessons in Electric Circuits] - A free series of textbooks on the subjects of electricity and electronics.
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