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One-port
In electrical circuit theory, a port is a pair of terminals connecting an electrical network or circuit to an external circuit, as a point of entry or exit for electrical energy. A port consists of two nodes (terminals) connected to an outside circuit which meets the ''port condition'' - the currents flowing into the two nodes must be equal and opposite. The use of ports helps to reduce the complexity of circuit analysis. Many common electronic devices and circuit blocks, such as transistors, transformers, electronic filters, and amplifiers, are analyzed in terms of ports. In multiport network analysis, the circuit is regarded as a "black box" connected to the outside world through its ports. The ports are points where input signals are applied or output signals taken. Its behavior is completely specified by a matrix of parameters relating the voltage and current at its ports, so the internal makeup or design of the circuit need not be considered, or even known, in determ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port Condition
In electrical circuit theory, a port is a pair of Terminal (electronics), terminals connecting an electrical network or Electronic circuit, circuit to an external circuit, as a point of entry or exit for electrical energy. A port consists of two node (circuits), nodes (terminals) connected to an outside circuit which meets the ''port condition'' - the Electric current, currents flowing into the two nodes must be equal and opposite. The use of ports helps to reduce the complexity of Network analysis (electrical circuits), circuit analysis. Many common electronic devices and circuit blocks, such as transistors, transformers, electronic filters, and amplifiers, are analyzed in terms of ports. In two-port network, multiport network analysis, the circuit is regarded as a "black box" connected to the outside world through its ports. The ports are points where input signals are applied or output signals taken. Its behavior is completely specified by a Matrix (mathematics), matrix of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Network Analysis (electrical Circuits)
A network, in the context of electrical engineering and electronics, is a collection of interconnected components. Network analysis is the process of finding the voltages across, and the currents through, all network components. There are many techniques for calculating these values. However, for the most part, the techniques assume linear components. Except where stated, the methods described in this article are applicable only to ''linear'' network analysis. Definitions Equivalent circuits A useful procedure in network analysis is to simplify the network by reducing the number of components. This can be done by replacing physical components with other notional components that have the same effect. A particular technique might directly reduce the number of components, for instance by combining impedances in series. On the other hand, it might merely change the form into one in which the components can be reduced in a later operation. For instance, one might transform a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-port Network
A two-port network (a kind of four-terminal network or quadripole) is an electrical network ( circuit) or device with two ''pairs'' of terminals to connect to external circuits. Two terminals constitute a port if the currents applied to them satisfy the essential requirement known as the port condition: the electric current entering one terminal must equal the current emerging from the other terminal on the same port.Gray, §3.2, p. 172Jaeger, §10.5 §13.5 §13.8 The ports constitute interfaces where the network connects to other networks, the points where signals are applied or outputs are taken. In a two-port network, often port 1 is considered the input port and port 2 is considered the output port. It's used in mathematical circuit analysis. Application The two-port network model is used in mathematical circuit analysis techniques to isolate portions of larger circuits. A two-port network is regarded as a " black box" with its properties specified by a matrix of n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Element
Electrical elements are conceptual abstractions representing idealized electrical components, such as resistors, capacitors, and inductors, used in the circuit analysis, analysis of electrical networks. All electrical networks can be analyzed as multiple electrical elements interconnected by wires. Where the elements roughly correspond to real components, the representation can be in the form of a Schematic diagram#Electronic industry, schematic diagram or circuit diagram. This is called a lumped-element model, lumped-element circuit model. In other cases, infinitesimal elements are used to model the network, in a distributed-element model. These ideal electrical elements represent real, physical Electronic component, electrical or electronic components but they do not exist physically and they are assumed to have ideal properties, while actual electrical components have less than ideal properties, a degree of uncertainty in their values and some degree of nonlinearity. To mode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waveguide Mode
A transverse mode of electromagnetic radiation is a particular electromagnetic field pattern of the radiation in the plane perpendicular (i.e., transverse) to the radiation's propagation direction. Transverse modes occur in radio waves and microwaves confined to a waveguide, and also in light waves in an optical fiber and in a laser's optical resonator. Transverse modes occur because of boundary conditions imposed on the wave by the waveguide. For example, a radio wave in a hollow metal waveguide must have zero tangential electric field amplitude at the walls of the waveguide, so the transverse pattern of the electric field of waves is restricted to those that fit between the walls. For this reason, the modes supported by a waveguide are quantized. The allowed modes can be found by solving Maxwell's equations for the boundary conditions of a given waveguide. Types of modes Unguided electromagnetic waves in free space, or in a bulk isotropic dielectric, can be described as a superp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inductance
Inductance is the tendency of an electrical conductor to oppose a change in the electric current flowing through it. The flow of electric current creates a magnetic field around the conductor. The field strength depends on the magnitude of the current, and follows any changes in current. From Faraday's law of induction, any change in magnetic field through a circuit induces an electromotive force (EMF) (voltage) in the conductors, a process known as electromagnetic induction. This induced voltage created by the changing current has the effect of opposing the change in current. This is stated by Lenz's law, and the voltage is called '' back EMF''. Inductance is defined as the ratio of the induced voltage to the rate of change of current causing it. It is a proportionality factor that depends on the geometry of circuit conductors and the magnetic permeability of nearby materials. An electronic component designed to add inductance to a circuit is called an inductor. It typ ... [...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 curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combination
In mathematics, a combination is a selection of items from a set that has distinct members, such that the order of selection does not matter (unlike permutations). For example, given three fruits, say an apple, an orange and a pear, there are three combinations of two that can be drawn from this set: an apple and a pear; an apple and an orange; or a pear and an orange. More formally, a ''k''-combination of a set ''S'' is a subset of ''k'' distinct elements of ''S''. So, two combinations are identical if and only if each combination has the same members. (The arrangement of the members in each set does not matter.) If the set has ''n'' elements, the number of ''k''-combinations, denoted as C^n_k, is equal to the binomial coefficient \binom nk = \frac, which can be written using factorials as \textstyle\frac whenever k\leq n, and which is zero when k>n. This formula can be derived from the fact that each ''k''-combination of a set ''S'' of ''n'' members has k! permutations so P^n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unbalanced Circuit
In electrical engineering, an unbalanced circuit is one in which the transmission properties between the ports of the circuit are different for the two poles of each port. It is usually taken to mean that one pole of each port is bonded to a common potential (single-ended signalling) but more complex topologies are possible. This common point is commonly called ''ground'' or ''earth'' but it may well not actually be connected to electrical ground at all. Unbalanced circuits are to be contrasted to balanced circuits where the transmission paths are impedance balanced (the impedances are identical). Examples Passive filter The figure shows two versions of a simple low-pass filter, unbalanced version (A) and balanced version (B). Both circuits have exactly the same effect as filters, they have the same transfer function. However, on the unbalanced circuit, the bottom pole of the input port is connected directly to the bottom pole of the output port. Thus, the impedance betwe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bridge Circuit
A bridge circuit is a topology of electrical circuitry in which two circuit branches (usually in parallel with each other) are "bridged" by a third branch connected between the first two branches at some intermediate point along them. The bridge was originally developed for laboratory measurement purposes and one of the intermediate bridging points is often adjustable when so used. Bridge circuits now find many applications, both linear and non-linear, including in instrumentation, filtering and power conversion. The best-known bridge circuit, the Wheatstone bridge, was invented by Samuel Hunter Christie and popularized by Charles Wheatstone, and is used for measuring resistance. It is constructed from four resistors, two of known values R1 and R3 (see diagram), one whose resistance is to be determined Rx, and one which is variable and calibrated R2. Two opposite vertices are connected to a source of electric current, such as a battery, and a galvanometer is connected across t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Box Attenuator
A box (plural: boxes) is a container used for the storage or transportation of its contents. Most boxes have flat, parallel, rectangular sides. Boxes can be very small (like a matchbox) or very large (like a shipping box for furniture), and can be used for a variety of purposes from functional to decorative. Boxes may be made of a variety of materials, both durable, such as wood and metal; and non-durable, such as corrugated fiberboard and paperboard. Corrugated metal boxes are commonly used as shipping containers. Most commonly, boxes have flat, parallel, rectangular sides, making them rectangular prisms; but boxes may also have other shapes. Rectangular prisms are often referred to colloquially as "boxes." Boxes may be closed and shut with flaps, doors, or a separate lid. They can be secured shut with adhesives, tapes, or more decorative or elaborately functional mechanisms, such as a catch, clasp or lock. Types Packaging Several types of boxes are used in packaging and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Generator (circuit Theory)
A generator in electrical circuit theory is one of two ideal elements: an ideal voltage source, or an ideal current source. These are two of the fundamental electrical element, elements in circuit theory. Real electrical generators are most commonly modelled as a non-ideal source consisting of a combination of an ideal source and a resistor. Voltage generators are modelled as an ideal voltage source in series with a resistor. Current generators are modelled as an ideal current source in parallel with a resistor. The resistor is referred to as the internal resistance of the source. Real world equipment may not perfectly follow these models, especially at extremes of loading (both high and low) but for most purposes they suffice. The two models of non-ideal generators are interchangeable, either can be used for any given generator. Thévenin's theorem allows a non-ideal current source model to be converted to a non-ideal voltage source model and Norton's theorem allows a non-i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
