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Blackman's Theorem
Blackman's theorem is a general procedure for calculating the change in an impedance due to feedback in a circuit. It was published by Ralph Beebe Blackman in 1943, was connected to signal-flow analysis by John Choma, and was made popular in the extra element theorem by R. D. Middlebrook and the asymptotic gain model of Solomon Rosenstark. Blackman's approach leads to the formula for the impedance ''Z'' between two selected terminals of a negative feedback amplifier as Blackman's formula: :Z = Z_D \frac \ , where ''ZD'' = impedance with the feedback disabled, ''TSC'' = loop transmission with a small-signal short across the selected terminal pair, and ''TOC'' = loop transmission with an open circuit across the terminal pair. The loop transmission also is referred to as the return ratio. Blackman's formula can be compared with Middlebrook's result for the input impedance ''Zin'' of a circuit based upon the extra-element theorem: :Z_ = Z^_ \left \frac\right/math> where: :Z\ is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ralph Beebe Blackman
Ralph Beebe Blackman (August 29, 1904 – May 24, 1990) was an American mathematician and engineer who was among the pioneers of the information age along with Claude E. Shannon, Hendrik Wade Bode, and John Tukey. Blackman graduated from the California Institute of Technology in 1926 and started work at Bell Labs, Bell Laboratories the same year. His early research were in the fields of hearing, acoustics and mechanical filters. Later he focused on applied mathematics, specifically Network analysis (electrical circuits), linear networks and Negative feedback amplifier, feedback amplifiers. Starting in 1940, Blackman worked on data smoothing for Fire-control system#Anti-aircraft fire control, anti-aircraft fire control systems. In 1963 Blackman was elected an Institute of Electrical and Electronics Engineers#Membership and member grades, IEEE Fellow. Books * * Patents * * * * * * * * * See also Blackman's theorem References California Ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal-flow Graph
A signal-flow graph or signal-flowgraph (SFG), invented by Claude Shannon, but often called a Mason graph after Samuel Jefferson Mason who coined the term, is a specialized flow graph, a directed graph in which nodes represent system variables, and branches (edges, arcs, or arrows) represent functional connections between pairs of nodes. Thus, signal-flow graph theory builds on that of directed graphs (also called digraphs), which includes as well that of oriented graphs. This mathematical theory of digraphs exists, of course, quite apart from its applications. i SFGs are most commonly used to represent signal flow in a physical system and its controller(s), forming a cyber-physical system. Among their other uses are the representation of signal flow in various electronic networks and amplifiers, digital filters, state-variable filters and some other types of analog filters. In nearly all literature, a signal-flow graph is associated with a set of linear equations. Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Choma (professor)
John Choma was Professor and Chair of Electrical Engineering-Electrophysics at the University of Southern California. Choma held B.S., M.S., and Ph.D. degrees in electrical engineering from the University of Pittsburgh The University of Pittsburgh (Pitt) is a public state-related research university in Pittsburgh, Pennsylvania. The university is composed of 17 undergraduate and graduate schools and colleges at its urban Pittsburgh campus, home to the universit .... His graduate theses were: * "Design of a Transistor Phasemeter," M.S. Thesis, University of Pittsburgh, 1965. * "Stability Analysis of Class C Transistor Amplifiers," Ph. D. Dissertation, University of Pittsburgh, 1969. Choma joined the USC faculty in 1980. He taught undergraduate and graduate courses in Network analysis (electrical circuits), electrical circuit theory, Electronic filter, filters, and Integrated circuit design#Analog design, analog integrated electronics, and advised industry in subjects relating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extra Element Theorem
The Extra Element Theorem (EET) is an analytic technique developed by R. D. Middlebrook for simplifying the process of deriving driving point and transfer functions for linear electronic circuits. Much like Thévenin's theorem, the extra element theorem breaks down one complicated problem into several simpler ones. Driving point and transfer functions can generally be found using Kirchhoff's circuit laws. However several complicated equations may result that offer little insight into the circuit's behavior. Using the extra element theorem, a circuit element (such as a resistor) can be removed from a circuit and the desired driving point or transfer function found. By removing the element that most complicates the circuit (such as an element that creates feedback), the desired function can be easier to obtain. Next two correctional factors must be found and combined with the previously derived function to find the exact expression. The general form of the extra element theorem i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asymptotic Gain Model
In analytic geometry, an asymptote () of a curve is a line such that the distance between the curve and the line approaches zero as one or both of the ''x'' or ''y'' coordinates tends to infinity. In projective geometry and related contexts, an asymptote of a curve is a line which is tangent to the curve at a point at infinity. The word asymptote is derived from the Greek ἀσύμπτωτος (''asumptōtos'') which means "not falling together", from ἀ priv. + σύν "together" + πτωτ-ός "fallen". The term was introduced by Apollonius of Perga in his work on conic sections, but in contrast to its modern meaning, he used it to mean any line that does not intersect the given curve. There are three kinds of asymptotes: ''horizontal'', ''vertical'' and ''oblique''. For curves given by the graph of a function , horizontal asymptotes are horizontal lines that the graph of the function approaches as ''x'' tends to Vertical asymptotes are vertical lines near which the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solomon Rosenstark
Solomon (; , ),, ; ar, سُلَيْمَان, ', , ; el, Σολομών, ; la, Salomon also called Jedidiah ( Hebrew: , Modern: , Tiberian: ''Yăḏīḏăyāh'', "beloved of Yah"), was a monarch of ancient Israel and the son and successor of David, according to the Hebrew Bible and the Old Testament. He is described as having been the penultimate ruler of an amalgamated Israel and Judah. The hypothesized dates of Solomon's reign are 970–931 BCE. After his death, his son and successor Rehoboam would adopt harsh policy towards the northern tribes, eventually leading to the splitting of the Israelites between the Kingdom of Israel in the north and the Kingdom of Judah in the south. Following the split, his patrilineal descendants ruled over Judah alone. The Bible says Solomon built the First Temple in Jerusalem, dedicating the temple to Yahweh, or God in Judaism. Solomon is portrayed as wealthy, wise and powerful, and as one of the 48 Jewish prophets. He is also the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Return Ratio
The return ratio of a dependent source in a linear electrical circuit is the ''negative'' of the ratio of ''the current (voltage) returned to the site of the dependent source'' to ''the current (voltage) of a replacement independent source''. The terms ''loop gain'' and ''return ratio'' are often used interchangeably; however, they are necessarily equivalent only in the case of a single feedback loop system with unilateral blocks. Calculating the return ratio The steps for calculating the return ratio of a source are as follows: # Set all independent sources to zero. # Select the dependent source for which the return ratio is sought. # Place an independent source of the same type (voltage or current) and polarity in parallel with the selected dependent source. # Move the dependent source to the side of the inserted source and cut the two leads joining the dependent source to the independent source. # For a voltage source the return ratio is minus the ratio of the voltage a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
