Impedance match - Impedance match Electricity It is usually very important to transfer power from one stage of an electronic device to the next. To transfer the maximum amount of power, the output impedance of one stage must be the same as the input impedance of the next stage. Impedance is the resistance of a circuit to alternating current. If a small impedance is connected to a big impedance, then the power that can pass through the connection is limited by the larger impedance. To solve this problem, engineers use combinations of transformers, resistors, inductors and capacitors. Impedances matched by transformers are used for high power circuits. A transformer converts alternating current at one voltage to another voltage, however the power remains the same, except for conversion losses. The.
Impedance - Impedance In electrical engineering, impedance is a measure for the manner and degree a component resists the flow of electrical current if a given voltage is applied. It is denoted by the symbol Z and is measured in ohms. See also reactance, inductance. For a practical layman's introduction, see nominal impedance. If the applied voltage is constant, capacitors act like insulators and inductors act like conductors; the impedance is then due to resistors alone and is a real number equal to the component's resistance R. If the applied voltage is changing over time (as in an AC circuit), then the component may affect both the phase and the amplitude of the current, due to inductors and capacitors inside the component. In this case, the impedance is.
Impedance mismatch - Impedance mismatch Impedance mismatch is a problem in electrical engineering that occurs when two transmission lines or circuits with different impedances are connected. This can cause signal reflection resulting in attenuation and noise. See also impedance matching. In programming terminology it refers to the attempt to connect two systems that have very different conceptual bases, most commonly when trying to use a SQL database from an object oriented program. Christopher J. Date would argue that a truly relational DBMS would pose no such problem, as domains and classeses are essentially one and the same thing. Another significant impedance mismatch in programming occurs between the domain objects and the user interface..
Impedance matching - Impedance matching Table of contents showTocToggle("show","hide") 1 General 2 Power transfer 3 Transmission lines 4 Impedance matching devices General Whenever a source of electicity, such as a signal source or a radio transmitter, operates into a load, optimum power is delivered to the load when the impedance of the load is equal to the internal impedance of the source. Arranging this is called impedance matching. Power transfer To demonstrate this, consider a source whose open circuit voltage is Vsource and whose internal impedance is Rsource ohms. Assume this source is connected to a load of Rload ohms. The resulting circuit can ve visualised as a perfect voltage source of Vsource volts driving two series connected resistors (Rsource and Rload) then flowing back to the zero volt.
Cable impedance - Cable impedance When radio frequency signals are transmitted via coaxial cable or ribbon cable, the impedance of the cable is significant in determining the load placed on the source and the efficiency of the transmission. Provided the internal impedance of the source and the impedance of the load or termination of the cable are equal, it is possible to manufacture a cable which will present a constant impedance at both ends, regardless of the length of the cable segment. This impedance is called the characteristic impedance of the cable. Thus, a 50 ohm coaxial cable, terminated in a non-inductive 50 ohm resistor, will present a 50 ohm impedance to whatever equipment is connected to its other end, regardless of the cable length. The most common impedances of.
Characteristic impedance - Characteristic impedance In radio communications, characteristic impedance (Z0) of a uniform transmission line is the impedance of a circuit that, when connected to the output terminals of a line of arbitrary length, causes the line to appear infinitely long. A uniform line terminated in its characteristic impedance will have no standing waves, no reflections from the end, and a constant ratio of voltage to current at a given frequency at every point on the line. If the line is not uniform, the iterative impedance must be used. The characteristic impedance of a linear, homogeneous, isotropic, dielectric propagation medium free of electric charge is given by the relation where μ is the magnetic permeability and ε is the electric permittivity of the medium. Where the magnetic permeability and.
Wave impedance - Wave impedance Wave impedance: At a point in an electromagnetic wave, the ratio of the electric field strength to the magnetic field strength. Note 1: If the electric field strength is expressed in volts per meter (V/m) and the magnetic field strength is expressed in ampere-turns per meter (A·t / m), the wave impedance will have the units of ohms. The wave impedance, Z , of an electromagnetic wave is given by the following equation, where μ is the magnetic permeability and ε is the electric permittivity: For free space, these values are 4Ï€ × 10-7 H/m (henries per meter) and (1/36Ï€) F/m (farads per meter), from which 120Ï€ ohms (≈377Ω) is obtained. In dielectric materials, the wave impedance is 377/n, where n is the refractive index..
Nominal impedance - Nominal impedance In electrical engineering, the nominal impendance of an input or ouput is the impedance of the output or input (respectively) that it is designed to accept. This article is intended to be a layman's introduction, and focuses on audio frequencies at which cable impedance is not significant. See impedance for a more technical discussion. See also impedance matching, cable impedance. Most equipment is designed to operate with the internal impedance of a signal source roughly equal to the impedance of the input to which it is connected. This provides the most efficient coupling, and is best in most but not all situations. The nominal impedance is the assumed impedance for the purpose of deciding whether two pieces of equipment are compatible for connection, and is.
Jack plug - was the original intention of the design. A considerable variety of line plugs and panel sockets is available, including plugs suiting various cable sizes, right angle plugs, and both plugs and sockets in a variety of price ranges and with current capacities up to about 15 amperes for the 1/4" version. Non-standard sizes, both diameters and lengths, are also available from some manufacturers, and are used when it is desired to restrict the availability of matching connectors. Several obsolete versions of the 1/4" jack plug exist, including: A two-pin version, consisting of two mono 6.5mm jack plugs at a centre spacing of 1". The socket versions of these can be used with normal jack plugs provided the plug bodies are not too large, but the plug version will only mate with.
Inductor - it makes the change more gradual. When a sinusoidal alternating current flows through an inductor, a sinusoidal alternating voltage (or electromotive force, abbr. emf) is induced. The amplitude of the emf is related to the amplitude of the current and to the frequency of the sinusoid by the following equation. V = I × Ï‰L where ω is the angular frequency of the sinusoid defined in terms of the frequency f as ω = 2Ï€f The term ωL is known as inductive reactance, which is denoted by the symbol XL and is the positive imaginary component of impedance. Table of contents showTocToggle("show","hide") 1 Construction 2 History 3 See also 4 Synonyms Construction An inductor is usually constructed as a coil of conducting material, usually copper wire. A core of ferrous material.
Voltage standing wave ratio - maximum to minimum voltage in a standing wave pattern. Note: The VSWR is a measure of impedance mismatch between the transmission line and its load. The higher the VSWR, the greater the mismatch. The minimum VSWR, i.e., that which corresponds to a perfect impedance match, is unity. Source: from Federal Standard 1037C and from MIL-STD-188 The VSWR is also defined as the ratio of Maximum voltage to minimum voltage in a transmission medium. VSWR = Vmax/Vmin Where, Vmax = Voltage level of the transmitted wave Vmin = Voltage level of the reflected wave If the characteristic impedance of the medium is equal to load impedance then VSWR is equals to 1. If the characteristic impedance (Z0) is less than the load impedance (Zl) then VSWR is greater than 1..
Gateway - with another network that uses different protocols. A gateway may contain devices such as protocol translators, impedance matching devices, rate converters, fault isolators, or signal translators as necessary to provide system interoperability. It also requires that mutually acceptable administrative procedures be established between the two networks. A protocol translation/mapping gateway interconnects networks with different network protocol technologies by performing the required protocol conversions. Loosely, a computer configured to perform the tasks of a gateway. Source: from Federal Standard 1037C and from MIL-STD-188 Gateway is also a San Diego, California-based computer company founded in 1985..
Glossary of telecommunications transmission terms - [clockwise] polarized wave]] -- ring latency -- scattering -- scintillation -- serial transmission -- shadow loss -- simplex operation -- skip distance -- skip zone -- sky wave -- smooth Earth -- space diversity -- sporadic E -- sunspot -- surface wave -- synchronous transmission -- time block -- trapped electromagnetic wave -- troposphere -- tropospheric scatter -- tropospheric wave -- undisturbed day -- virtual height -- waveguide Transmission Lines artificial transmission line -- balanced line -- building out -- bundle -- cable -- Category 3 -- Category 4 -- Category 5 -- coaxial cable (coax) -- composite cable -- direct-buried cable -- directional coupler -- electrical length -- fiber optic cable -- field wire -- filled cable -- group delay -- hybrid cable -- land line -- lay length --.
Fanout - general allows gates to be wired directly together with no additional interfacing circuitry required. A perfect logic gate would have infinite input impedance and zero output impedance, allowing a gate to drive any number of further gates. However, since real-world fabrication technologies exhibit less than perfect characteristics, in reality a limit will be reached where a gate cannot drive any more current into subsequent gates - attempting to do so causes the voltage to fall below the level defined for the logic level on that wire, causing errors. The fanout is simply the number of gates that can be connected before this occurs. CMOS logic has a very high fanout - at least 50 to 100, whereas the older TTL logic gates were limited to perhaps 2 to 10, depending on.
Fade - its end (fade-out), or gradually increases from silence at the beginning (fade-in). It can be used as either a verb or noun. A fader is any device used to accomplish this task, especially when it is a knob or button that slides along a track or slot. A knob which rotates is usually not considered a fader, although it is electrically and functionally equivalent. A fader can be either analogue, directly controlling the resistance or impedance to the source; or digital, numerically controlling a digital signal processor (DSP). A crossfader essentially functions like two faders connected side-by-side to each other, but in opposite directions. It allows a DJ to fade one source out while fading another source in at the same time. This is extremely useful when trying to beatmatch two.
Field effect transistor - exists even without any voltage applied to the gate. When one then applies a voltage to the gate, the channel is depleted, which reduces the current flow through the device. In essence the depletion mode device is equivalent to a normally closed switch, while the enhancement mode device is equivalent to a normally open switch. Historically, n-channel MOSFETs tended to be smaller and therefore cheaper to produce. These were the driving principles in the design of NMOS logic which uses n-channel MOSFETs exclusively. However, NMOS logic consumes power even when no switching is taking place, unlike CMOS logic which combines n-channel and p-channel MOSFETs on a single chip. With advances in technology, CMOS logic displaced NMOS in the 1980s to become the preferred choice for digital chips. MOSFETs can only be.
Flute - of a hole bounces in and out of the hole. Some engineers have called this a fluidic multivibrator, because it forms a mechanical analogy to an electronic circuit called a multivibrator. The stream beats against the air in a resonator, usually a tube. The player changes the pitch of the flute by changing the effective length of the resonator. This is done either by closing holes, or more rarely, with a slide similar to a trombone's slide. Because the air-stream is lower mass than most of the resonators used in instruments, it can beat faster, but with less momentum. As result, flutes tend to be softer, but higher-pitched than other sound generators of the same size. To be louder, a flute must use a larger resonator, and a wider air-stream. A.
Forward echo - by reflections caused by splices or other discontinuities in the transmission medium (e.g. , optical fiber, twisted pair, or coaxial tube). In metallic lines, they may be supported by impedance mismatches between the source or load and the characteristic impedance of the transmission medium. Source: from Federal Standard 1037C and from MIL-STD-188.
Full blood count - the blood. The machine prints out, and/or sends to a computer, the results. Blood counting machines work by sampling blood, and sucking a standard amount through a small tube. Within this tube, there are sensors that count the number of cells going through it, and can identify the type of cell. The two main sensors used are light detectors, and electrical impedance. Because an automated cell counter samples and counts so many cells, it gives a very precise estimate. However, with certain abnormal cells in the blood, they may be identified incorrectly, and not be as accurate as a manual count. Automated blood counting machines include the Sysmex XE-2100 and the Celldyne range. Manual blood count Counting chambers, that hold a specified volume of diluted blood (as their are far too.
Electrical network - find a steady state solution. This is a solution where all nodes conform to Kirchhoff's Current Law and the voltages across and through each element of the circuit conform to the voltage/current equations governing that element. Once the steady state solution is found, the operating points of each element in the circuit are known. For a small signal analysis, every non-linear element can be linearized around its operation point to obtain the small-signal estimate of the voltages and currents. This is an application of Ohm's Law. The resulting linear circuit matrix can be solved with Gauss-Jordan elimination. Piece-wise linear approximation This type of simulator uses piece-wise linear approximations of the equations governing the elements of a circuit. This approximation comes down to splitting the circuit into two parts: a completely linear.
