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Nullor
A nullor is a theoretical two-port network consisting of a nullator at its input and a norator at its output.The name "nullor" was introduced in Carlin. H. J . "Singular network elements", Tech. Doc. Rept. RADC-TDR-63-511, Polytechnic Inst. of Brooklyn, Jan.1964; later published in the March 1964 issue of the IEEE Transactions on Circuit Theory, Volume 11, Issue 1, pp.67-72 https://doi.org/10.1109/TCT.1964.1082264. Nullors represent an ideal amplifier, having infinite current, voltage, transconductance and transimpedance gain. Its transmission parameters are all zero, that is, its input–output behavior is summarized with the matrix equation : \begin v_1\\ i_1 \end = \begin 0 & 0 \\ 0 & 0 \end \begin v_2\\ i_2 \end In negative-feedback circuits, the circuit surrounding the nullor determines the nullor output in such a way as to force the nullor input to zero. Inserting a nullor in a circuit schematic imposes mathematical constraints on how that circuit must behave, fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current Mirror
A current mirror is a circuit designed to copy a current through one active device by controlling the current in another active device of a circuit, keeping the output current constant regardless of loading. The current being "copied" can be, and sometimes is, a varying signal current. Conceptually, an ideal current mirror is simply an ideal ''inverting current amplifier'' that reverses the current direction as well. Or it can consist of a current-controlled current source (CCCS). The current mirror is used to provide bias currents and active loads to circuits. It can also be used to model a more realistic current source (since ideal current sources don't exist). The circuit topology covered here is one that appears in many monolithic ICs. It is a Widlar mirror without an emitter degeneration resistor in the follower (output) transistor. This topology can only be done in an IC, as the matching has to be extremely close and cannot be achieved with discretes. Another topology i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nullator
In electronics, a nullator is a theoretical linear, time-invariant one-port ''defined'' as having zero current and voltage across its terminals. Nullators are strange in the sense that they simultaneously have properties of both a short (zero voltage) and an open circuit (zero current). They are neither current nor voltage sources, yet both at the same time. {{cite book , author=Verhoeven C J M van Staveren A Monna G L E Kouwenhoven M H L & Yildiz E , title=Structured electronic design: negative feedback amplifiers , year= 2003 , publisher=Kluwer Academic , location=Boston/Dordrecht/London , isbn=1-4020-7590-1 , pages=§2.2.1.1 pp. 30–32 , url=https://books.google.com/books?id=p8wDptzCMrUC&pg=PA24 Inserting a nullator in a circuit schematic imposes a ''mathematical constraint'' on how that circuit must behave, forcing the circuit itself to adopt whatever arrangements needed to meet the condition. For example, the inputs of an ideal operational amplifier An operational ampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Norator
In electronics, a norator is a theoretical linear, time-invariant one-port which can have an arbitrary current and voltage between its terminals. A norator represents a controlled voltage or current source with infinite gain. {{cite book , author=Verhoeven C J M van Staveren A Monna G L E Kouwenhoven M H L & Yildiz E , title=Structured electronic design: negative feedback amplifiers , year= 2003 , publisher=Kluwer Academic , location=Boston/Dordrecht/London , isbn=1-4020-7590-1 , pages=§2.2.1.1 pp. 30–32 , url=https://books.google.com/books?id=p8wDptzCMrUC&pg=PA24 Inserting a norator in a circuit schematic provides whatever current and voltage the outside circuit demands, in particular, the demands of Kirchhoff's circuit laws. For example, the output of an ideal opamp behaves as a norator, producing nonzero output voltage and current that meet circuit requirements despite a zero input. A norator is often paired with a nullator In electronics, a nullator is a theoretical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bipolar Junction Transistor
A bipolar junction transistor (BJT) is a type of transistor that uses both electrons and electron holes as charge carriers. In contrast, a unipolar transistor, such as a field-effect transistor, uses only one kind of charge carrier. A bipolar transistor allows a small current injected at one of its terminals to control a much larger current flowing between the terminals, making the device capable of amplification or switching. BJTs use two p–n junctions between two semiconductor types, n-type and p-type, which are regions in a single crystal of material. The junctions can be made in several different ways, such as changing the doping of the semiconductor material as it is grown, by depositing metal pellets to form alloy junctions, or by such methods as diffusion of n-type and p-type doping substances into the crystal. The superior predictability and performance of junction transistors quickly displaced the original point-contact transistor. Diffused transistors, alon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Processing and Ronald W. Schafer, the principles of signal processing can be found in the classical numerical analysis techniques of the 17th century. They further state that the digital re ...
Signal processing is an electrical engineering subfield that focuses on analyzing, modifying and synthesizing '' signals'', such as sound, images, and scientific measurements. Signal processing techniques are used to optimize transmissions, digital storage efficiency, correcting distorted signals, subjective video quality and to also detect or pinpoint components of interest in a measured signal. History According to Alan V. Oppenheim Alan Victor Oppenheim''Alan Victor Oppenheim'' was elected in 1987 [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Theory
Control theory is a field of mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a desired state, while minimizing any ''delay'', ''overshoot'', or ''steady-state error'' and ensuring a level of control stability; often with the aim to achieve a degree of optimality. To do this, a controller with the requisite corrective behavior is required. This controller monitors the controlled process variable (PV), and compares it with the reference or set point (SP). The difference between actual and desired value of the process variable, called the ''error'' signal, or SP-PV error, is applied as feedback to generate a control action to bring the controlled process variable to the same value as the set point. Other aspects which are also studied are controllability and observability. Control theory is used in control sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Components
An electronic component is any basic discrete device or physical entity in an electronic system used to affect electrons or their associated fields. Electronic components are mostly industrial products, available in a singular form and are not to be confused with electrical elements, which are conceptual abstractions representing idealized electronic components and elements. Electronic components have a number of electrical terminals or leads. These leads connect to other electrical components, often over wire, to create an electronic circuit with a particular function (for example an amplifier, radio receiver, or oscillator). Basic electronic components may be packaged discretely, as arrays or networks of like components, or integrated inside of packages such as semiconductor integrated circuits, hybrid integrated circuits, or thick film devices. The following list of electronic components focuses on the discrete version of these components, treating such packages as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Output Resistance
Output may refer to: * The information produced by a computer, see Input/output * An output state of a system, see state (computer science) * Output (economics), the amount of goods and services produced ** Gross output in economics, the value of net output or GDP plus intermediate consumption ** Net output in economics, the gross revenue from production less the value of goods and services * Power (physics) or Work (physics) output of a machine * Dependent variable Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or dema ... of a function, in mathematics * ''Output'' (album) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Effect
The Early effect, named after its discoverer James M. Early, is the variation in the effective width of the base in a bipolar junction transistor (BJT) due to a variation in the applied base-to-collector voltage. A greater reverse bias across the collector–base junction, for example, increases the collector–base depletion width, thereby decreasing the width of the charge carrier portion of the base. Explanation In Figure 1, the neutral (i.e. active) base is green, and the depleted base regions are hashed light green. The neutral emitter and collector regions are dark blue and the depleted regions hashed light blue. Under increased collector–base reverse bias, the lower panel of Figure 1 shows a widening of the depletion region in the base and the associated narrowing of the neutral base region. The collector depletion region also increases under reverse bias, more than does that of the base, because the base is more heavily doped than the collector. The principle gov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kirchhoff's Current Law
Kirchhoff's circuit laws are two equalities that deal with the current and potential difference (commonly known as voltage) in the lumped element model of electrical circuits. They were first described in 1845 by German physicist Gustav Kirchhoff. This generalized the work of Georg Ohm and preceded the work of James Clerk Maxwell. Widely used in electrical engineering, they are also called Kirchhoff's rules or simply Kirchhoff's laws. These laws can be applied in time and frequency domains and form the basis for network analysis. Both of Kirchhoff's laws can be understood as corollaries of Maxwell's equations in the low-frequency limit. They are accurate for DC circuits, and for AC circuits at frequencies where the wavelengths of electromagnetic radiation are very large compared to the circuits. Kirchhoff's current law This law, also called Kirchhoff's first law, or Kirchhoff's junction rule, states that, for any node (junction) in an electrical circuit, the sum of curre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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