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Thin Film Resistor Deposition, Rollie R. Herzog

Masters Theses

"Thin film techniques may be the key to future miniaturization of electrical equipment. The purpose of this thesis was to develop procedures for deposition of thin film resistors and to test these deposited resistors. Starting with a vacuum system, equipment was designed and built to hold and heat the substrate, monitor the substrate temperature and deposited resistance, and to evaporate the material to be deposited. Resistors were deposited and tested for resistance between resistors, capacitance between resistors, and resistance of resistors. A heat aging test was also used comparing resistors with and without a silicon monoxide coating"--Abstract, page ii.

Linvill's Model As Applied To P-N Junction Photo-Diodes, Rudy Michael Chittenden

Masters Theses

"The problem undertaken in this study is to present a performance evaluation of Linvill's model as it pertains to the p-n junction photo-diode. The evaluation is performed by comparing the distributed mathematical solutions, the solution obtained using Linvill's lumped model, and the experimental measurement of the transient voltage rise across a photo-diode due to a unit-step pulse of light incident on the junction. Despite the absence of a suitable light source for use in the experimental measurement, it is concluded that Linvill's model provides an excellent means to determine the risetime of a photo-diode. This is provided that the photo-diode …

Analog Simulation Of A Synchronous Machine, J. Derald Morgan

Masters Theses

"The problem presented here is a study by an analog computer simulation of a synchronous machine under balanced three phase, short-circuit conditions. The purpose is to obtain a solution that is more accurate than one obtained by approximate methods using transient and subtransient reactances as is often done. This simulation is accomplished by using an idealized synchronous machine. The equations relating voltage and currents in the machine, as well as speed and torque, are presented for simulation. The equations for the machine include the saliency of one member, as well as the effect of speed and the damper windings. A …

A Feedback Compensator Design For Linear Control Systems, Thsai-Ten Lin

Masters Theses

"The compensation process in control system engineering is indispensable. The addition of a compensator to a fixed plant can often make the system meet certain specifications easily. In this study an attempt was made to use a general purpose digital computer to design a feedback compensator. The method developed is first to determine the minimum gain of the amplifier and the number of compensator poles and zeros based on the given specifications. then free hand root-loci are plotted, with several combinations of possible compensation variables. These data are used as the open-loop transfer function from which the poles and zeros …

A Computer Approach To Transistor Circuit Design, Kwok Chee Hong

Masters Theses

"The design of amplifiers is usually approached through experimental study. This thesis proposes a mathematical approach, using a digital computer to predict the performance of an active transistor circuit (a frequency equalizer circuit to compensate for the RIAA recording frequency characteristics) prior to the actual construction of the physical system. The simple but powerful computer analysis method will be based upon the nodal equations of the complete circuit. The primary aim is to design a circuit which would give a desired frequency-gain characteristic. The complete set of simultaneous complex nodal equations describing the circuit operation is then written. Based on …

Active Band-Pass Filters Using Twin-Tee Networks, Terry B. Watson

Masters Theses

"The primary objective of this thesis was the design and construction of a set of filters to determine the spectral energy density of random signal data in the spectrum from 10 cps to 20 kcps. The statement of the problem placed rather exacting conditions on the cost and performance of the equipment, and these conditions were met to the extent detailed in the following pages. A secondary objective was the investigation of techniques to improve the performance of band-pass active filters using resistive-capacitive feedback networks. This objective was not achieved to the author's satisfaction, although several promising ideas were discovered"--Abstract, …

A Study Of The Effect Of Surface Beveling On Silicon Rectifiers, Gary L. Voorhis

Masters Theses

"The problem in this thesis is to experimentally obtain voltage vs distance data for different angles of bevel, to determine the optimum bevel angle on the basis of minimum surface electric field, and also to determine the location of the maximum surface electric field with respect to the p-n junction. Experimental equipment is constructed and results are graphically illustrated. It is concluded that in general the maximum surface electric field decreased as the bevel angle decreased, that neglecting practical considerations the optimum bevel angle was 3⁰, and that the maximum surface electric field occurred near, but not at the p-n …

Measurement Of Stray Load Loss Of D.C. Machines, Kanaiyalal Ramanlal Shah

Masters Theses

"For many years the standard practice, in calculation of conventional efficiency of d.c. machines, has been to include stray load losses as equal to 1% of the output. This assumption may be true for large, compensated d.c. machines but it is known to be small for smaller, uncompensated, general-purpose, industrial-type machines of open design. An A.I.E.E. Committee on Rotating Machines was formed to investigate whether the present practice of assigning 1% for the stray load loss is justified or not. They reached a conclusion, reported in 1949, after investigating 243 stray loss tests on different motors ranging from 1/2 hp …

An Evaluation Of Demonstrations On Inductor Theory, Boyd Warner Wasson

Dissertations and Theses @ UNI

The writer sought an improved approach for teaching theory of electronics to high school students. This approach was intended to require less expense and time needed to provide classroom instruction on electrical theory.

The purpose of this study were to:

(1) Prepare a number of demonstrations to illustrate phenomena associated with coils or inductors and their use in practical electronics.

(2) Prepare equipment and gather parts needed to perform demonstrations. Ease of construction and economy were important considerations.

(3) Evaluate the effectiveness of the demonstrations on student comprehension and the ability to apply information taught.

Transient Gamma Radiation Effects On Resistors, Harold T. Cates

Electrical and Computer Engineering ETDs

If a resistor in a circuit is exposed to a transient gamma radiation pulse, the condition of the circuit will be modified by passing from its steady state condition before radiation to a state of excitation that will depend upon the intensity and duration of the radiation pulse. When the radiation pulse is over, the circuit will then relax to its previous condition of equilibrium within a characteristic time constant.

When energetic radiation, such as gamma radiation, charged particles, or neutrons, strikes matter, it causes several effects which alter the properties of the target material. Some of the effects that …

Antennas In Or At The Surface Of A Conducting Medium At Vlf, George R. Swain

Electrical and Computer Engineering ETDs

To meet the requirements of a number of military operations and to facilitate some types of geophysical exploration, it is necessary to communicate between points beneath or at the surface of the earth or of the ocean. This need has led to the investigation of antennas for use in or at the surface of conducting media. The purpose of this paper is to briefly survey the previous work on such antennas, to extend the concepts of effective length and other merit factors to antennas in or near a conducting medium, and to analyze the electrical behavior of the toroid and …

An Experimental Determination Of Ultrasonic Wave Velocities In Plastics As Functions Of Temperature, Ned D. Arnold

Electrical and Computer Engineering ETDs

This thesis reports the results of an experimental investigation into the effects of temperature on the velocity of ultrasonic longitudinal acoustic waves through various plastics.

The Driving-Point Impedance Of An Electrically Short Cylindrical Antenna In The Ionosphere, William E. Blair

Electrical and Computer Engineering ETDs

1.0 Since the advent of satellites, there has been con­siderable interest in both military and peacetime uses of satellites as research instruments, communication relays, and transportation vehicles. In most cases, it is necessary to communicate with the satellites for purposes of trans­mitting and receiving information.

A Method Of Process Identification Of Certain Linear Control Systems, Eugene A. Aronson

Electrical and Computer Engineering ETDs

No abstract provided.

A Study Of Electro-Magnetic Wave Propagation In Inhomogeneous Media, Thomas N. C. Wang

Electrical and Computer Engineering ETDs

The central problem of this work will be the development of several approximation methods and the application thereof to the solution of second order linear differential equations which arise in connection with the propagation of electromagnetic radiation in inhomogeneous media. Chapter I is an introduction to the problem. Maxwell’s equations are written down and it is assumed that both σ, the conductivity, and ɛ, the permittivity, are scalar functions or position. Often the above function characterizing some or the properties of matter vary in physical situations. For example, in waveguides, there may be inserted layers of dielectric material along the …

The Multi-Terminal Hall Generator, Sang S. Pak

Electrical and Computer Engineering ETDs

This thesis describes a study undertaken to maximize the Hall generator efficiency. A mathematical solution is obtained for a multi-terminal Hall generator, and an analytical technique is developed for determining the optimum values of parameters to maximize the generator efficiency. An equivalent circuit is developed for an N output-terminal Hall generator, and the efficiency expression is obtained as a function of sample dimension, conductivity and Hall coefficient of the material, and magnetic field strength. Some of the results have been checked experimentally with indium antimonide and fields up to 21.5 kilogauss. An efficiency of 40% was obtained experimentally for a …

A Kerr Cell System For Measuring The Amplitude Of High-Voltage Nonrecurring Pulses, Donald C. Wunsch

Electrical and Computer Engineering ETDs

There are at present several conventional techniques and systems to measure the peak amplitude of high-voltage pulses. Three of the prin­cipal techniques are:

1. Potential dividers in conjunction with some type of low-voltage recording system.

2. High-voltage oscilloscopes with low sensitivity.

3. Sphere gaps with predetermined breakover voltages.

Potential dividers of many types have been developed. These include resistive voltage dividers, capacitive voltage dividers, and combination resistive and capacitive dividers. The different designs have usually been developed to eliminate some error in measurement. Different types of resistive windings have been designed to minimize self-inductance. Shields have been designed to reduce …

The Design Criteria Of A Phoswich Transducer., Richard L. Crawford

Electrical and Computer Engineering ETDs

This dissertation is an experimental and theoretical treatise on the design criteria of a phoswich transducer. The major emphasis is on the application in a gamma-ray spectrometer. The conversion efficiency, gamma-ray cross sections, response to charged particles, luminescence decay time, spectral response and physical qualities are discussed, in considerable detail, in making the optimum choices for the inorganic crystal and the organic phosphor which will act as the charged particle anticoincident shield. The effect of the thickness of the anticoincident shield on resolution, the percentage of gamma-rays absorbed, the percentage of gamma-rays that are atten­uated in energy and the lower …

Predicting Current Gain Degradation In Npn Silicon Transistors After Irradiation By High-Energy Neutrons, Jerry A. Hood

Electrical and Computer Engineering ETDs

The damage discussed in this report is permanent and remains after all transient ionization has decayed. The damage which predominantly affects the electrical characteristics of a transistor is the creation of "vacancies" and "interstitials" in the lattice structure. These defects are created when an atom is knocked from its position and leaves a vacancy in the lattice. The atom comes to rest in a position out of the lattice structure and is known as interstitial. These atoms are knocked from their positions by the irradiating neutrons or by an interstitial traveling through the crystal. These defects occur in localized clusters …

Electric Fields From Airborne Vertical And Horizontal Dipoles At Very-Low Frequencies, A. H. Garry Gibson

Electrical and Computer Engineering ETDs

A gap exists in present-day knowledge of the electric fields in the earth which are radiated from elevated antenna structures in the earth-air-ionosphere waveguide. It is the purpose of this paper to present a method of estimating the electric field at the earth-air boundary, caused by elevated antenna structures, and to show the existence of new phenomena that may lead to an improved design of communication systems.

Optimum Zero-Memory Nonlinear Filter, Benjamin Shaw-Hu Wang

Masters Theses

“The purpose of this report is to review the basic work described by Zadeh insofar as systems of class N₁ are concerned and to apply his general results to a specific problem in which a non-linear filter is mandatory simply because the linear filter is essentially ineffective. The ineffectiveness stems from the fact that the autocorrelation function of the signal plus the noise has essentially the same variational character as the signal alone. Therefore, the transfer function of the linear filter turns out to be simply a constant. Thus, the output of the linear filter is just an attenuated …

Compensator Design For Unity Feedback Systems Using An Analytical Method, Chang-Yu Wu

Masters Theses

“In control systems engineering it is frequently necessary to compensate a fixed plant whose transfer function cannot be changed. Usually the characteristics of the resulting system are established in terms of steady-state and transient performance specifications. Generally it is necessary to insert a compensator which insures stability as well as satisfies the specifications.

In this thesis an analytical method is developed to determine the transfer function of the compensator in order to satisfy the following set of specifications. The fixed system is assumed to contain one non-linearity, saturation. The input to the saturable device is constrained in a statistical …

Radiation Characteristics Of A U-Slot Antenna., Richard Paul Brueggemann

Masters Theses

"The radiation equations for a simple rectangular slot antenna are derived as a function of the field distribution in the slot. The electric field distribution in the slot is then formulated as a function of the aperture dimensions. The U-shaped slot antenna is described as an extension of the rectangular slot theory and the actual field is measured in the slot for comparison.

The far field equations a.re derived for the U-slot antenna similar to those for the rectangular slot antenna and are evaluated using the formulated distributions in the slot for antennas of two different electrical sizes. The equations …

An Investigation Of The Adaptability Of The Linvill Model For Transistor Synthesis, John A. Reagan

Masters Theses

"The Linvill transistor model may be used for transistor synthesis if the model accurately approximates transistor response and may be readily simulated on an analog computer. Experiments were performed on a transistor to determine the Linvill model parameters. The transistor's large-signal transient response was investigated by pulsing the emitter with a current that drove the transistor from the active region of operation into saturation. The same problem solved experimentally was then solved analytically by replacing the transistor with the Linvill model. The experiment was then simulated on an analog computer by using the equations that govern the Linvill model's response. …

On Optimum Receiver Using Decision Theory, Philip T. Tai

Masters Theses

“In recent years communication engineers have given increased attention to the study of communication through random media. The name random is used to describe a medium the properties of which are stated only in a statistical sense. For example the impulsive response of a certain medium may only be known as one of an ensemble of possible impulsive responses; the particular member of interest being drawn up according to some statistical rule. In other words there exists some "uncertainty" concerning the characteristic description of the medium. Significant work on these problems has been done by Price and Turin. Related work …

An Analysis Of The Simulated Inductande Obtained From Forward Biased Semiconductor Diodes., Everett Harold Vannoy

Masters Theses

"The problem undertaken in this thesis is to study the simulated inductance observed in forward-biased abrupt junction p-n diodes with a highly doped p region and a nearly intrinsic n region and show that it is due to conductivity modulation. Unlike other analyses of this phenomenon, a voltage step is applied to the diode in such a direction as to forward bias it and the behavior of the injected minority carriers are observed. By comparing the resultant current through the diode to the relationship predicted by the equivalent circuit of the diode, an expression is obtained for the simulated inductance. …

The Resolution Of Two Known Signals In White Gaussian Noise., Peter Cheng-Fang Wang

Masters Theses

"The problem of resolving two signals F1(t) and F2(t) in white Gaussian noise n(t) is treated here as a problem in statistical decision theory. We assume a situation in which one of two similar signals is present and an observer is asked to make a decision concerning which of the signals is present with a tolerable probability of error. The observer is allowed to use the best system which he can design for this particular purpose. Of course, this observation will be disturbed by noise and therefore, the observer is led to ambiguous selections. It is apparent that the optimum …

Time Optimum Switching Zones In Multiple-Valued Control Systems, Jack Leroy Crawford

Masters Theses

"Present control system theory provides the criteria necessary to bring a second-order single-valued system to rest in a minimum time after a step input. The bang-bang type controller has been developed to obtain this optimum response.

However, existing theory fails to provide the necessary information to obtain the optimum response from a second-order rotational system when multiple values of angular position are allowed. This thesis extends the control theory to include these multiple-valued systems by showing the existence of what are called optimum switching zones. These zones predict which of the infinite number of switching curves in a multiple-valued system …

Synthesis Of Unity-Gain Rc Networks From Second Degree Transfer Functions., Ronald L. Mcnally

Masters Theses

"A synthesis procedure is presented which realizes second order open circuit transfer functions. This procedure is developed using parallel networks. The transfer functions for each parallel network are obtained by use of separation parameters. Two constraints are used in the development: first, the realized network must be an RC network; second, the desired multiplicative gain constant must be realized. With these constaints a parameter space is developed which aids in the selection of the proper parallel networks to be combined. Necessary and sufficient conditions are developed which are used to test the transfer functions. The realization simply consists of the …

High Order Bang Bang Control System., Shing-Chou Pi

Masters Theses

"The problem undertaken in this thesis is to find a representation of a nonlinear controller to minimize the response time of a limited input plant whose transfer function has N negative real poles. The extension of the phase-space method to automatic control systems described by high-order differential equations with a general high-order input is considered.

The design utilizes a maximum effort controller whose switching time is determined by the concept of switching hypersurfaces of the system in N-dimensional phase space and the concept of a distance function, which is & geometric length between the initial state point and the switching …