62 Matching Results

Search Results

Advanced search parameters have been applied.

Determination of the Actual Contact Surface of a Brush Contact

Description: The number of partial contact surfaces of a brush-ring contact is measured by means of a statistical method. The particular brush is fitted with wicks - that is, insulated and cemented cylinders of brush material, terminating in the brush surface. The number of partial contact surfaces can be computed from the length of the rest periods in which such wicks remain without current. Resistance measurements enable the determination of the size of the contact surfaces. The pressure in the actual contact surface of a recently bedded brush is found to be not much lower than the Brinell hardness of the brush.
Date: August 1, 1944
Creator: Holm, Ragnar
Partner: UNT Libraries Government Documents Department

Investigation of the Operating Properties of the Leakage Current Anemometer

Description: Freedom from inertia, erosion of electrodes, and reaction make the leakage current particularly appropriate for the measurement of flow velocities in gases. Apparatus previously described has now been improved by reducing the size of the electrodes by one -thousandth, as is necessary aerodynamically, and by increasing the magnitude of the current from 1000 to 10,000 times; the latter result was obtained.by use of mercury high-pressure lamps set up at the one focal point of an ellipsoidal reflector with the cathodes arranged at the other focal point or by use of suitable X-ray radiation. Families of calibration curves were taken with a number of vivid tests conditions of the greatest variety and the operating properties of the instrument were widely elucidated by calculation of the sensitivity to fluctuation; this was done at first for operation at stationary conditions only; due to the freedom from inertia the instationary conditions were thus also given. Accordingly, the leakage current anemometer ought to be appropriate for investigations of turbulence,.
Date: October 1, 1947
Creator: Fucks, Wilhelm
Partner: UNT Libraries Government Documents Department

Piezoelectric Instruments of High Natural Frequency Vibration Characteristics and Protection Against Interference by Mass Forces

Description: The exploration of the processes accompanying engine combustion demands quick-responding pressure-recording instruments, among which the piezoelectric type has found widespread use because of its especially propitious properties as vibration-recording instruments for high frequencies. Lacking appropriate test methods, the potential errors of piezoelectric recorders in dynamic measurements could only be estimated up to now. In the present report a test method is described by means of which the resonance curves of the piezoelectric pickup can be determined; hence an instrumental appraisal of the vibration characteristics of piezoelectric recorders is obtainable.
Date: February 1, 1943
Creator: Gohlka, Werner
Partner: UNT Libraries Government Documents Department

A 018μm Cmos Transmitter for Ecg Signals

Description: Electrocardiography (ECG) signal transmitter is the device used to transmit the electrical signals of the heart to the remote machine. These electrical signals are ECG signals caused due to electrical activities in the heart. ECG signals have very low amplitude and frequency; hence amplification of the signals is needed to strengthen the signal. Conversion of the amplified signal into digital information and transmitting that information without losing any data is the key. This information is further used in monitoring the heart.
Date: December 2013
Creator: Kakarna, Tejaswi
Partner: UNT Libraries

SOLSTOR Description and User's Guide

Description: Abstract: This report describes the computer simulation code SOLSTOR. The code simulates energy systems in which electricity is generated by either a photovoltaic (PV) system or a wind turbine generator (WTG). Storage may or may not be present. Backup electricity, if needed, is provided either from a utility grid or from a fuel-burning generator. SOLSTOR minimizes the life cycle cost of providing energy by choosing the optimal solar or wind system component sizes. Rates for electricity purchased from the grid can include time-of-day (TOD) energy charges as well as time-of-day peak demand changes. Sell-back to the grid of excess collected energy is also considered.
Date: March 1981
Creator: Aronson, Eugene A.; Caskey, David L. & Caskey, Bill C.
Partner: UNT Libraries Government Documents Department

U.S. Access to Japanese Technical Literature: Electronics and Electrical Engineering, Selected Presentations, Volume 1

Description: Abstract: On June 24-25, 1985, NBS and IEEE cosponsored a seminar at NBS to examine the need fox improved access to Japanese technical information and to explore possible app. aches to satisfy those needs. To limit the discussion to practical dimensions, the technical subject matter was restricted to electrical and electronics engineering. The program was designed to provide an opportunity for individuals representing Congress, the practicing engineering community, industry, and the educational community to voice their concerns and their needs. This proceedings volume contains selected presentations made at the seminar plus the visual aids used by each speaker.
Date: January 1986
Creator: Brady, Edward L.
Partner: UNT Libraries Government Documents Department

Catenary Chart 3

Description: Chart of catenary curve ordinates: "The curve gives approximate values of sag at all points on the catenary curve expressed in per cent of the center sag. The error is negligible for all spans in which the center sag is less than 10% of the span length." It is enlarged from figures in NBS discussion of national electrical safety code (handbook H39).
Date: August 7, 1944
Creator: United States. National Bureau of Standards.
Partner: UNT Libraries Government Documents Department

Conductor Loading Nomograph Chart 1B

Description: Chart related to conductor loading showing vertical, transverse and conductor loads in pounds per linear feet of conductor. It is enlarged from figures in NBS discussion of national electrical safety code (handbook H39).
Date: August 7, 1944
Creator: United States. National Bureau of Standards.
Partner: UNT Libraries Government Documents Department

Engineering process instructions and development summary MC3642 thermal battery

Description: The MC3642 is a dual channel thermal battery used on the DE1010/W85 Command Disable Controller. It utilizes the CalCaCrO{sub 4} electrochemical system. The electrical requirements of this battery are as follows: RISE TIME PEAK VOLTAGE ACTIVE LIFE LOAD Channel 1 - 1.0 Sec. Max. 34 Volts 10 Sec. Min. 40.0 Ohms to 20 Volts above 20 Volts Channel 2 - .350 Sec. Max. 42 Volts 10 MSec. Min. 6.5 Ohms to 23 Volts above 23 Volts The battery consists of 14 cells connected in series (Channel 2) and 12 cells connected in series (Channel 1). Each cell is composed of an anode fabricated from a bimetallic sheet (0.005{double_prime} thick calcium on 0.005{double_prime} thick iron substrate), a depolarizer-electrolyte-binder (DEB) pellet and a heat pellet. Activation is achieved by mechanical primer. Optimum battery performance is achieved with a 35155/10 DEB pellet weighing .80g and a heat pellet, weighing 1.30 grams, of 88/12 heat powder.
Date: June 1, 1981
Creator: Jacobs, D.
Partner: UNT Libraries Government Documents Department

Advanced Processing of CdTe- and CuInxGa1-xSe2-Based Solar Cells: Final Report: 18 April 1995 - 31 May 1998

Description: This report summarizes work performed by the University of South Florida Department of Electrical Engineering under this subcontract. The Cadmium telluride(CdTe) portion of this project deals with the development of high-efficiency thin-filmed CdTe solar cells using fabrication techniques that are suitable for manufacturing environments.
Date: January 13, 1999
Creator: Morel, D. L.; Ferekides, C. S.; Bhatt, R.; Jayapalan, A.; Komin, V.; Lin, H. et al.
Partner: UNT Libraries Government Documents Department

Needs, opportunities, and options for large scale systems research

Description: The Office of Energy Research was recently asked to perform a study of Large Scale Systems in order to facilitate the development of a true large systems theory. It was decided to ask experts in the fields of electrical engineering, chemical engineering and manufacturing/operations research for their ideas concerning large scale systems research. The author was asked to distribute a questionnaire among these experts to find out their opinions concerning recent accomplishments and future research directions in large scale systems research. He was also requested to convene a conference which included three experts in each area as panel members to discuss the general area of large scale systems research. The conference was held on March 26--27, 1984 in Pittsburgh with nine panel members, and 15 other attendees. The present report is a summary of the ideas presented and the recommendations proposed by the attendees.
Date: October 1, 1984
Creator: Thompson, G.L.
Partner: UNT Libraries Government Documents Department

Graduate Automotive Technology Education (GATE) Center for Hybrid Electric Drivetrains and Control Strategies

Description: Beginning the fall semester of 1999, The University of Maryland, Departments of Mechanical and Electrical Engineering and the Institute for Systems Research served as a U.S. Department of Energy (USDOE) Graduate Automotive Technology Education (GATE) Center for Hybrid Electric Drivetrains and Control Strategies. A key goal was to produce a graduate level education program that educated and prepared students to address the technical challenges of designing and developing hybrid electric vehicles, as they progressed into the workforce. A second goal was to produce research that fostered the advancement of hybrid electric vehicles, their controls, and other related automotive technologies. Participation ended at the University of Maryland after the 2004 fall semester. Four graduate courses were developed and taught during the course of this time, two of which evolved into annually-taught undergraduate courses, namely Vehicle Dynamics and Control Systems Laboratory. Five faculty members from Mechanical Engineering, Electrical Engineering, and the Institute for Systems Research participated. Four Ph.D. degrees (two directly supported and two indirectly supported) and seven Master's degrees in Mechanical Engineering resulted from the research conducted. Research topics included thermoelectric waste heat recovery, fuel cell modeling, pre- and post-transmission hybrid powertrain control and integration, hybrid transmission design, H{sub 2}-doped combustion, and vehicle dynamics. Many of the participating students accepted positions in the automotive industry or government laboratories involved in automotive technology work after graduation. This report discusses the participating faculty, the courses developed and taught, research conducted, the students directly and indirectly supported, and the publication list. Based on this collection of information, the University of Maryland firmly believes that the key goal of the program was met and that the majority of the participating students are now contributing to the advancement of automotive technology in this country.
Date: September 30, 2005
Creator: Holloway, David
Partner: UNT Libraries Government Documents Department

Mitigating PQ Problems in Legacy Data Centers

Description: The conclusions of this presentation are: (1) Problems with PQ in legacy data centers still exist and need to be mitigated; (2) Harmonics generated by non-linear IT load can be lowered by passive, active and hybrid cancellation methods; (3) Harmonic study is necessary to find the best way to treat PQ problems; (4) AHF's and harmonic cancellation transformers proved to be very efficient in mitigating PQ problems; and (5) It is important that IT leaders partner with electrical engineering to appropriate ROI statements, justifying many of these expenditures.
Date: June 1, 2011
Creator: Ilinets, Boris
Partner: UNT Libraries Government Documents Department

Supply-pollution (SP) loss in induction motor

Description: Power supply in the field is often noticeably polluted with various degrees of harmonics content and unbalanced voltages. In order to assess the energy loss caused by the supply pollution in the widely used induction motors, a method based on the air-gap torque power is discussed.
Date: July 1, 1995
Creator: Hsu, J.S.
Partner: UNT Libraries Government Documents Department