Vibrating-piston electrostatic field sensor.
Vibrating-piston electrostatic field sensor for Gemini program, examining design improvements including unity-feedback preamplifier, noise reduction devices, etc
ELECTROSTATIC FIELD↗
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Results for “PREAMPLIFIER”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Capacitance-coupled wiper increases potentiometer life
Capacitively-coupled wiper reduces the friction between the sliding contact and the potentiometer element in conventional potentiometers. A small preamplifier employed close to the wiper reduces errors caused by output cable capacitance. The device is friction free with resultant low wear and has high speed and high resolution.
Dimeff, J.↗
Low-cost, fast-response drive circuit for electromagnetic torque motors
Fast-response coil drive circuit, for electromagnetic torque motors, reduces the inductive coil time constant with a minimum of circuit sophistication. The low-cost modulator servoamplifier is used with a compatible preamplifier stage which provides the servo-loop function of summing, adjustable gain and compensation.
Zeller, J. R.↗
High resolution Ge/Li/ spectrometer reduces rate-dependent distortions at high counting rates
Modified spectrometer system with a low-noise preamplifier reduces rate-dependent distortions at high counting rates, 25,000 counts per second. Pole-zero cancellation minimizes pulse undershoots due to multiple time constants, baseline restoration improves resolution and prevents spectral shifts.
Brenner, R.↗
A new wideband traveling-wave maser system.
Wideband traveling wave maser SHF preamplifier system with high gain and low noise temperature operating in closed cycle liquid He refrigerator
Johnson, C. C.↗
Sixty-GHz integrated RF head Final report
Integrated 60.8 GHz RF receiver and low noise IF preamplifier development
Jones, W. S.↗
Biomedical sensing and display concept improves brain wave monitoring
Concept for increasing effectiveness of biomedical sensing and display promises greater monitoring capability while lessening high skill requirements in operating personnel. New concept overcomes deficiencies of current system by employing increased number of probes and microelectronic preamplifiers.
Trent, R. L.↗
RC filter with low distributed capacitance provides 60 db isolation at 500 MHz
Resistance-capacitance RC filter coupled to a high input impedance receiver preamplifier provides signal isolation from an RF transmitter. High isolation is achieved by minimizing the inductive impedance to ground and using the distributed capacitance of the filter components.
Cessna, J. R.↗
Inexpensive photon counting system with internal gate generator
Preamplifier-discriminator-gate generator in printed circuit for use with photomultipliers, noting pulse sensitivity and cost
Born, J.↗
A system for the automatic measurement and digital display of systolic and diastolic blood pressures
Basic components of system are - occluding cuff with mounted cuff microscope, cuff pump deflator, pressure transducer, preamplifier unit, electrocardiograph machine, an analog to digital convertor unit, and digital display unit. System utilizes indirect auscultatory method, based on Korotkoff sounds, for measurement.
Schulze, A. E.↗
Electronic amplifiers: A compilation
Several types of amplifiers and amplifier systems are considered. These include preamplifiers, high power amplifiers, buffer and isolation amplifiers, amplifier circuits, and general purpose amplifiers.
Source record↗
Development of improved pyroelectric detectors. Measurements of pyroelectric material characteristics and FET characteristics
Research was undertaken to improve the detectivity of the pyroelectric detector with the ultimate goal of operation at or near the temperature-noise limit. Two general areas of investigation were undertaken: (1) to improve responsivity through the use of new materials; and (2) to reduce noise through improved field effect transistor characteristics, and improved electroding of the pyroelectric material. FET's are being obtained from various manufacturers, evaulated, and selected units tested for evaluation of characteristics critical to their use as preamplifiers with pyroelectric detectors.
Weiner, S.↗
Operational testing of system for automatic sleep analysis
Tables on the performance, under operational conditions, of an automatic sleep monitoring system are presented. Data are recorded from patients who were undergoing heart and great vessel surgery. This study resulted in cap, electrode, and preamplifier improvements. Children were used to test the sleep analyzer and medical console write out units. From these data, an automatic voltage control circuit for the analyzer was developed. A special circuitry for obviating the possibility of incorrect sleep staging due to the presence of a movement artifact was also developed as a result of the study.
Kellaway, P.↗
Analysis of bioelectric records and fabrication of phototype sleep analysis equipment
A computer-analysis technique was used to evaluate the changes in the waking EEGs of 5 normal subjects which occurred during the oral administration of flurazepam hydrochloride (Dalmane). While the subjects were receiving the drug, there was an increase in the amount of beta (14-38 c/sec) activity in fronto-central EEG leads in all 5 subjects. This increase in beta activity was characterized by a highly consistent increase in the number of waves that occurred during an EEG recording interval of fixed duration and by a less consistent increase in average wave amplitude. There was no detectable change in mean EEG wavelength (frequency) within the beta frequency range. The EEG patterns reverted to their baseline condition during 2-3 weeks after withdrawal of the drug. Analysis of the alpha, theta and delta components of the EEG indicated no changes during or following administration of the drug. This study clearly illustrates the usefulness of specific computer-analysis techniques in the characterization and quantification of sleep-promoting drugs upon the EEG of the normal young adults in the waking state. Two preamplifiers and 150 EEG monitoring caps with electrodes were delivered to MSC.
Kellaway, P.↗
A low power X-ray diffractometer for soil analysis in remote locations employing a multiwire proportional counter detector array.
A low power X-ray powder diffraction system suitable for remote mineralogical analysis of lunar, planetary, or asteroid soils has been designed. A one Curie Fe-55 source provides a monochromatic X-ray beam of 5.9 keV. Seeman-Bohlin focusing geometry is employed in the camera, allowing peak detection to proceed simultaneously at all angles and obviating the need for moving parts. The detector system is an array of 500-600 proportional counters with a wire-spacing of 1 mm. An electronics unit comprising preamplifier, postamplifier, window discriminators, and storage flip-flops requiring only 3.5 milliwatts has been designed and tested. Total instrument power is less than 5 W.
Gregory, J. C.↗
A gamma ray monitor for the OSO-7 spacecraft.
A NaI(T2) gamma ray spectrometer with a CsI(Na) charged particle and anti-Compton shield has been developed for the spacecraft. The spacecraft telemetry system employs a 800 Hz clock and reads data out on a basic 32-word (byte) Main Frame cycle. The data from the instrument include spectral data, X-ray data, and housekeeping data. The gamma ray pulses from the anode of the central detector flow through the front end electronics, where they are amplified by a charge sensitive preamplifier. The admission of the desired gamma ray into the data stream is controlled by a linear gate.
Higbie, P. R.↗
Fast-neutron spectrometer developments
Li6 sandwich-type neutron spectrometer is equipped with proportional counter for particle identification. System uses current-sensitive preamplifiers to minimize pile-up of gamma-ray and particle pulses.
Moler, R. B.↗
Binary-selectable detector holdoff circuit
High-speed switching circuit protects detectors from sudden, extremely-intense backscattered radiation that results from short-range atmospheric dust layers, or low-level clouds, entering laser/radar field of view. Function of circuit is to provide computer-controlled switching of photodiode detector, preamplifier power-supply voltages, in approximately 10 nanoseconds.
Kadrmas, K. A.↗