Thevenin equivalent

The diode voltage is 0.75251 V, and the diode current is 4.248 mA. The diode voltage and current of this circuit are the same as the diode voltage and current of the previous example. This result should be expected since the Thevenin equivalent of V1, Rl, R2, and R3 in this exercise is exactly the same as the circuit of die previous example. ... 

Capture and PSpice can be used to easily calculate the Norton and Thevenin equivalents of a circuit. The method we will use is the same as if we were going to find the equivalent circuits in the lab. We will make two measurements, the open circuit voltage and the short circuit current. The Thevenin resistance is then the open circuit voltage divided by the short circuit current. This will require us to create two circuits, one to find the open circuit voltage, and the second to find the short circuit current. In this example, we will find the Norton and Thevenin equivalent circuits for a DC circuit. This same procedure can be used to find the equivalent circuits of an AC circuit (a circuit with capacitors or inductors). However, instead of finding the open circuit voltage and short circuit current using the DC Nodal Analysis, we would need to use the AC analysis. 

We will convert this circuit into the Thevenin equivalent ... 

Note that only at the output terminals n-n are the Thevenin and Norton equivalents the same. In other words, at the output terminals n-n the voltage and current of the Thevenin equivalent circuit and the Norton equivalent circuit are identical. 

Mobile Studio (MS) Lab 4— Thevenin Equivalent Orcuit and Max Power Transfer 1. Mobile Studio and Instrumentation Board... 

However, this may not be quite the case (another case of bad notation). In fact, the author suggests a relaxed condition for an MSA, namely one that scatters (in total) only as much as it absorbs—that is, one that is constrained only by condition 1 above (most antennas scatter more in total than they absorb, never less). As we shall see, this relaxed condition leads to a much broader class of antennas, some of which are truly noteworthy. The three examples presented above are excellent illustrations of these concepts. However, let us briefly remind the reader about the Thevenin equivalent circuit as it applies to receiving antennas. 

It is well known that any receiving antenna can be described by a Thevenin equivalent circuit, shown in Fig. 2.13. Here the power delivered to the load impedance Zl will always correctly represent the power being absorbed by the antenna, while the power being lost in represents power being reradiated somewhere in space by the antenna. However, the antenna may actually scatter considerably more power than is being lost in Za-... 

Fig. 2.13 The Thevenin equivalent circuit for a receiving antenna always yields the correct power delivered to the load impedance Zl. The power lost in the antenna impedance Za represents power scattered somewhere, not necessarily in the back direction. Additional scattering not accounted for by Za will in general take place.

Thus, this antenna is truly an MSA in the rigorous classical sense. In addition, the Thevenin equivalent circuit will correctly describe all of these features as far as the array in Example I is concerned. 

It was further demonstrated that if we relaxed the conditions above to merely the first, namely that the antenna should scatter no more total energy than it absorbs, it could lead to antennas with virtually no residual scattering (but not necessarily so). An interesting feature of this class of antenna is that the Thevenin equivalent circuit may no longer correctly predict that the total scattered power as merely associated with under all load conditions. This should be accepted as a fact of Ufe, and failing to realize this can lead to fatal mistakes. 

The second scheme is shown in Fig. D.13. Here aU elements are loaded directly with the same load impedances Zi and exposed to an incident plane wave (note no connectors are necessary, strictly speaking). From the Thevenin equivalent circuit shown in the insert we then have... 

Min BG, Kresh JM, Fich S, Kostis JB, Welkowitz W (1978) Relation between computed zero-load aortic flow and cardiac muscle mechanics. J. Biomech 80 227-235 Sandler J, Dodge HT (1963) Left ventricular tension and stress in man. Circ Res 13 91 Shastri SJ (1969) A thevenin equivalent model of the left ventricle derived from hemodynamic measurements obtained by use of a ventricular assist pump. Ph D Thesis, New Brunswick, NJ Rutgers Univ... 

The modeling of an accumulator or battery of accumulators is a highly complex task. There are many different approaches, which will be more or less appropriate depending on the objectives reqnired of the model. In order to replicate electrical behavior similar to that of a battery, we nse a model in the form of an equivalent electrical circuit. Many different circuits are put forward in the existing body of literature Thevenin equivalent circnit, improved Thevenin equivalent circuit, FreedomCar, etc. In all cases, the parameters nsed for these models are determined experimentally. 

The Thevenin equivalent circuit is the simplest combination, since it is the association of an ideal voltage source and a resistor connected in series. This is a much more realistic way of modeling a lead-acid battery. Indeed, the resistor illustrates the voltage drop due to the current passing through the components of the battery. In the case of LABs, this instantaneous voltage drop mainly results from the low electrical conductivity of electrolyte and is proportional to the current. But, such a simple combination does not account for the polarization of the electrodes happening later on, when the battery is operated. 

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