Twin-capacitive shaft angle encoder with analog output signal

A precision capacitive shaft encoder providing a dc signal corresponding to the angular position of a shaft is described. Two variable capacitances are coupled in tandem by a rotatable shaft. Each capacitor has a capacitance that varies linearly with a change in the angular position of the shaft. The sum of the two capacitances is always constant for any angular position of the shaft. Each capacitance is alternately coupled to a reference dc voltage and a discharge circuit. The capacitances are electrically coupled in series and the charge periodically acquired at the junction of the capacitance is a function of the position of the shaft. An error-compensating voltage is imposed on the junction when the capacitances are coupled to the reference voltages. The junction is coupled to sample-and-hold apparatus provided with a error-correcting circuit

Transient video signal recording with expanded playback Patent

Transient video signal tape recorder with expanded playbac

Microwave flaw detector Patent

Surface defect detection by reflected microwave radiation patter

Nondestructive testing of microtab welds

Introduction of sinusoidal signal across welded structure to determine reliability of integrated circuit connections is discussed. In-phase frequencies and quadrature frequency functions are used to evaluate weld reliability. Schematic diagram of test equipment and components is provided

Coaxial inverted geometry transistor having buried emitter

The invention relates to an inverted geometry transistor wherein the emitter is buried within the substrate. The transistor can be fabricated as a part of a monolithic integrated circuit and is particularly suited for use in applications where it is desired to employ low actuating voltages. The transistor may employ the same doping levels in the collector and emitter, so these connections can be reversed

Flight test results of the Strapdown hexad Inertial Reference Unit (SIRU). Volume 3: Appendices A-G

Results of flight tests of the Strapdown Inertial Reference Unit (SIRU) navigation system are presented. The fault tolerant SIRU navigation system features a redundant inertial sensor unit and dual computers. System software provides for detection and isolation of inertial sensor failures and continued operation in the event of failures. Flight test results include assessments of the system's navigational performance and fault tolerance. Selected facets of the flight tests are also described in detail and include some of the following: (1) flight test plans and ground track plots; (2) navigation residual plots; (3) effects of approximations in navigation algorithms; (4) vibration spectrum of the CV-340 aircraft; and (5) modification of the statistical FDICR algorithm parameters for the flight environment

Flight test results of the Strapdown hexad Inertial Reference Unit (SIRU). Volume 1: Flight test summary

Flight test results of the strapdown inertial reference unit (SIRU) navigation system are presented. The fault-tolerant SIRU navigation system features a redundant inertial sensor unit and dual computers. System software provides for detection and isolation of inertial sensor failures and continued operation in the event of failures. Flight test results include assessments of the system's navigational performance and fault tolerance

Flight test results of the strapdown hexad inertial reference unit (SIRU). Volume 2: Test report

Results of flight tests of the Strapdown Inertial Reference Unit (SIRU) navigation system are presented. The fault tolerant SIRU navigation system features a redundant inertial sensor unit and dual computers. System software provides for detection and isolation of inertial sensor failures and continued operation in the event of failures. Flight test results include assessments of the system's navigational performance and fault tolerance. Performance shortcomings are analyzed

Viability of the Use of Electromagnetic Induction to Predict Streambed Properties

This study examined whether electromagnetic induction is a reliable tool to predict various streambed properties, including water conductivity, water temperature, and hydraulic conductivity. The test site was along the North Loup River, outside of St. Paul, Nebraska. Electromagnetic induction was performed using a field portable, multi-frequency EMI tool. Hydraulic conductivity was measured using the falling-head permeameter test, and water temperature and conductivity were measured using handheld meters. The study found that there is a strong positive correlation between water conductivity and apparent electrical conductivity measured by electromagnetic induction. This relationship can be explored further through the analysis of spatial patterns in streambed sandbars

Viability of the Use of Electromagnetic Induction to Predict Streambed Properties

This study examined whether electromagnetic induction is a reliable tool to predict various streambed properties, including water conductivity, water temperature, and hydraulic conductivity. The test site was along the North Loup River, outside of St. Paul, Nebraska. Electromagnetic induction was performed using a field portable, multi-frequency EMI tool. Hydraulic conductivity was measured using the falling-head permeameter test, and water temperature and conductivity were measured using handheld meters. The study found that there is a strong positive correlation between water conductivity and apparent electrical conductivity measured by electromagnetic induction. This relationship can be explored further through the analysis of spatial patterns in streambed sandbars