scholarly journals A Modified General Diode Equation

Author(s):  
Pragnan Chakravorty

The general diode equation or the non-ideal diode equation is the foundation of circuit models of active devices for the past several decades. Apart from the effect of p-n junction, this equation also accounts for the series bulk resistance of a diode. Despite a reasonable agreement of the equation with measured VI characteristics, it is shown here that the equation is incompatible with basic theories of circuits and systems. Therefore, a modification in the equation is proposed to remove this incompatibility. This modified equation has an excellent agreement with the measured VI characteristics.

2021 ◽  
Author(s):  
Pragnan Chakravorty

The general diode equation or the non-ideal diode equation is the foundation of circuit models of active devices for the past several decades. Apart from the effect of p-n junction, this equation also accounts for the series bulk resistance of a diode. Despite a reasonable agreement of the equation with measured VI characteristics, it is shown here that the equation is incompatible with basic theories of circuits and systems. Therefore, a modification in the equation is proposed to remove this incompatibility. This modified equation has an excellent agreement with the measured VI characteristics.


2021 ◽  
Author(s):  
Pragnan Chakravorty

The general diode equation or the non-ideal diode equation is the foundation of circuit models of active devices for the past several decades. Apart from the effect of p-n junction, this equation also accounts for the series bulk resistance of a diode. Despite a reasonable agreement of the equation with measured IV characteristics, it is shown here that the equation is incompatible with basic theories of circuits and systems. Therefore, a modification in the equation is proposed to remove this incompatibility. This modified equation leads to a compact model of a p-n junction diode that has an excellent agreement with the measured IV characteristics.


2021 ◽  
Author(s):  
Pragnan Chakravorty

The general diode equation or the non-ideal diode equation is the foundation of circuit models of active devices for the past several decades. Apart from the effect of p-n junction, this equation also accounts for the series bulk resistance of a diode. Despite a reasonable agreement of the equation with measured VI characteristics, it is shown here that the equation is incompatible with basic theories of circuits and systems. Therefore, a modification in the equation is proposed to remove this incompatibility. This modified equation has an excellent agreement with the measured VI characteristics.


2001 ◽  
Vol 79 (6) ◽  
pp. 939-946 ◽  
Author(s):  
A Sinha ◽  
R Roychoudhury ◽  
Y P Varshni

Confined quantum systems have been studied by various authors over the past decades, by using various mathematical techniques. In this work, we derive the WKB quantization rules for quantum systems confined in an impenetrable spherical box of radius r0. We apply the proposed method to two systems explicitly, viz., the confined harmonic oscillator and the confined hydrogen atom. The results are found to be in reasonable agreement with those obtained by other methods. PACS No.: 03.65


A vast number of diverse analog circuit blocks have been arosed in the past few decades. A various active devices are Operational Amplifier (Op-Amp), Current Conveyor (CC), Operational Transconductance Amplifier (OTA), Differential Difference Current Conveyor (DDCC), Differential Difference Current Conveyor Transconductnace Amplifier (DDCCTA), Z-Copy Current Differencing Transconductance Amplifier (ZC-CDTA), Voltage Difference Transconductance Amplifier (VDTA) and so on. A review on Schmitt trigger circuits by using different active devices are presented in this paper since Schmitt trigger circuits are widely used in numerous applications such as in waveform generators, wave-shaping circuits, comparators, Bio-medical applications, analog processing systems, communication and instrumentation systems.


1999 ◽  
Author(s):  
Ying Chen ◽  
Hans Conrad

Abstract The zero-field viscosity of model ER fluids consisting of glass beads in silicone oil was determined as a function of average particles size (D¯ = 3–75 μm), volume fraction (ϕ = 0.1–0.3) and bimodal mixtures of two sizes. The viscosity increased with ϕ and decreased with D¯. The viscosity of the suspensions ηs in all cases was described reasonably well by the following relation:ηs=ηs,o(ϕ)+b(ϕ)D¯2/D¯3 where ηs,o(ϕ) and b(ϕ) are constants which increase with ϕ. Reasonable agreement with the Mooney crowding equation occurred for the single size particles, giving for the crowding factor k = 1.3 + 1.5/D¯. For ϕ < 0.2 the viscosity of the bimodal mixtures could be described by a modification of the Mooney equationηsηo=exp(2.76ϕ11-k1ϕ1)exp(2.76ϕ21-k2ϕ2) where ηo is the viscosity of the silicone oil, ϕi the volume fraction of each particle size Di and ki the normal crowding factor for that size. At ϕ = 0.3 the measured values of ηs for the bimodal mixtures became appreciably larger than those calculated from the modified equation. The decrease in particle size leads to both an increase in surface area of the particles per unit volume of the suspension and to a decrease in spacing (crowding); both factors probably contributed to the increase in ηs.


2009 ◽  
Vol 22 (12) ◽  
pp. 3303-3316 ◽  
Author(s):  
Bin Wang ◽  
Qinghua Ding ◽  
P. V. Joseph

Abstract The onset of the Indian summer monsoon (ISM) over the southern tip of the Indian peninsula [also known as monsoon onset over Kerala (MOK)] has been considered the beginning of India’s rainy season. The Indian Meteorological Department (IMD) makes an official prediction of ISM onset every year using a subjective method. Based on an analysis of the past 60-yr (1948–2007) record, the authors show that the onset date can be objectively determined by the beginning of the sustained 850-hPa zonal wind averaged over the southern Arabian Sea (SAS) from 5° to 15°N, and from 40° to 80°E. The rapid establishment of a steady SAS westerly is in excellent agreement with the abrupt commencement of the rainy season over the southern tip of the Indian peninsula. In 90% of the years analyzed, this simple and objective index has excellent agreement with the onset dates that are subjectively defined by the IMD. There are only 3 yr of the past 60 yr during which the two onset dates differ by more than 10 days, and none of them perfectly reflects the MOK. A prominent onset precursor on the biweekly time scale is the westward extension of the convection center from the equatorial eastern Indian Ocean toward the southeast Arabian Sea. On the intraseasonal time scale, the onset tends to be led by northeastward propagation of an intraseasonal convective anomaly from the western equatorial Indian Ocean. The objective determination of the onset based on the SAS low-level westerly is a characteristic representation of the complex process of the ISM onset. Given its objectiveness and its representation of the large-scale circulation, the proposed new onset definition provides a useful metric for verifying numerical model performance in simulating and predicting the ISM onset and for studying predictability of interannual variations of the onset.


1980 ◽  
Vol 53 (1) ◽  
pp. 116-125
Author(s):  
Lawrence A. Wood

Abstract A survey of published experimental work on the modulus of natural rubber crosslinked by dicumyl peroxide permits a comparison with the results and molecular interpretations obtained in recent NBS work. Excellent agreement was found among values of the shear modulus G at the same crosslinking when the crosslinking is calculated from the amount of decomposed dicumyl peroxide. The types of deformation included torsion as well as uniaxial extension and compression. G increases linearly with crosslinking (except at the lowest degrees) with a slope from 5 to 15 percent greater than that predicted by the simple statistical theory. Data of Mullins demonstrated that at each degree of crosslinking the value of G is intermediate between 2C1 and 2(C1+C2) where C1 and C2 are the Mooney-Rivlin constants. Measurements of equilibrium swelling at a given degree of crosslinking are in reasonable agreement with each other. However, the entropy components of the modulus and the sub-chain density calculated from swelling measurements are appreciably greater than those calculated from crosslinking or from direct mechanical measurements. They increase linearly with crosslinking. It is concluded that the number of sub-chains effective in limiting swelling is greater than that effective in direct mechanical measurements.


1982 ◽  
Vol 97 ◽  
pp. 305-306
Author(s):  
W. A. Sherwood ◽  
G. V. Schultz ◽  
E. Kreysa ◽  
H.-P. Gemünd

During the past decade many kinds of optical surveys have discovered hundreds of quasars most of which (∼90 %) are radio quiet (<10 mJy at 5 GHz). We have observed two samples of quasars brighter than 17m.6 found by their emission lines and by their ultraviolet excess. We have also selected quasars with redshifts known to be greater than 3.00. A brief description of the observing technique is given by Sherwood et al. (1981b). We have compared our millimetre photometry of flat radio spectrum quasars with that of Ennis and Werner and find excellent agreement. For four of the 8 sources in common the data have been published: Kreysa et al. (1980) and Jones et al. (1981). In addition, analysis of our “noise” shows it to be white, gaussian distributed about zero. The three samples are summarized as follows.


2007 ◽  
Vol 1030 ◽  
Author(s):  
Michael Grove ◽  
Donal Hayes ◽  
Virang Shah

AbstractPatterning materials over large areas on flexible plastic or metal substrates, and on rigid ones, where multiple layers of different materials are being applied in order to create active devices brings with it the real challenge of accurate materials placement [1]. The additive process of printing expensive functional materials reduces costs associated with the losses of subtractive processing, but focuses the technological necessity on the precision of materials alignments on the target substrates. During the past decade, both materials and their print processing have developed to a near commercial level for optical and electronic devices. Industrial success will be assured when their production enjoys the economies of scale that large area processing can bring. Ink jet technology has developed in the last twenty-five years to a level of sophistication that is now adequate for the challenges of processing large area substrates for optical and electronic devices. Some equipment and processing will be covered in this paper.


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