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Search Publications by: Bryan C. Waltrip (Fed)

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Displaying 26 - 50 of 110

Development of a 60 Hz Power Standard using SNS Programmable Josephson Voltage Standards

April 7, 2008
Author(s)
Charles J. Burroughs, Samuel Benz, Paul Dresselhaus, Yonuk Chong, Bryan C. Waltrip, Thomas L. Nelson, J. Williams, D. Henderson, P. Patel, Luis Palafox, Ralf Behr
We are implementing a new standard for 60 Hz power based on precision sinusoidal reference voltages from two independent Programmable Josephson Voltage Standards (PJVS) (one for voltage and one for current). The NIST PJVS systems use series arrays of

Evaluation of a Capacitance Scaling System

December 1, 2007
Author(s)
Svetlana Avramov-Zamurovic, Andrew D. Koffman, Bryan C. Waltrip, Yicheng Wang
A capacitance scaling system from 10 nF to 100 mF [1], [2] has been implemented at the National Institute of Standards and Technology (NIST). Standard four-terminal-pair (4TP) capacitors are characterized using a capacitance scaling calibration procedure

Development of a 60 Hz Power Standard using SNS Programmable Josephson Voltage Standards

July 14, 2006
Author(s)
Charles J. Burroughs, Samuel Benz, Paul Dresselhaus, Yonuk Chong, Bryan C. Waltrip, Thomas L. Nelson, J. Williams
We are implementing a new standard for 60 Hz mains power based on precision sinusoidal reference voltages from two independent Programmable Josephson Voltage Standards (PJVS) (one for voltage and one for current). Our NIST PJVS systems are based on

A Four-Terminal Current Shunt with Calculable AC Response

August 30, 2004
Author(s)
Owen B. Laug, T. M. Souders, Bryan C. Waltrip
The design of a 0.1 Ohm, four-terminal current shunt with calculable frequency dependence up to 1 MHz is described. It is intended for use as a standard for current measurements up to 10 A rms with the primary purpose of being able to tie alternating

A Low Thermal Error Sampling Comparator for Accurate Settling Measurements

January 1, 2004
Author(s)
David I. Bergman, Bryan C. Waltrip
A new sampling comparator design employing a signal-dependent biasing scheme is described. The dynamic bias significantly reduces signal-induced thermal error in the comparator. The circuit design approach is applicable to comparators intended for use in

A Low Noise Latching Comparator Probe for Waverform Sampling Applications

May 1, 2002
Author(s)
David I. Bergman, Bryan C. Waltrip
A new latching comparator probe is described. The probe is being developed as part of an effort to extend voltage measurement capability in the 10 Hz to 1 MHz frequency range. The probe offers an input voltage range of ±10V, input impedance of 1 MΩ}, and

Improved Time-Base for Waveform Parameter Estimation

August 31, 2001
Author(s)
Bryan C. Waltrip, Owen B. Laug, Gerard N. Stenbakken
An improved gated oscillator time-base and associated auto-calibration algorithm for use in a high-accuracy waveform acquisition system are descrigbed. The time-base architecture consists of a stable 100 MHz gated oscillator, 24-bit counter chain, and a

Design of an Active MM-Wave Concealed Object Imaging System

August 1, 2001
Author(s)
Nicholas Paulter, Erich N. Grossman, Gerard N. Stenbakken, Bryan C. Waltrip, Shalva Nolen, Carl D. Reintsema
The research and design of an active millimeter-wave concealed object imaging system is described. Several illumination and detection methods were analyzed via computer simulation to assess the effects of system parameters on the signal-to-noise ratio of

A Capacitance Measurement System Using an Inductive Voltage Divider (IVD) Bridge

July 1, 2001
Author(s)
Bryan C. Waltrip, Andrew D. Koffman, S. Avramov
A new system to characterize the magnitude and phase characteristics of 1 pF to 1 uF capacitance standards over the 50 Hz to 100 kHz frequency range is described. The system has been developed to provide measurement support for LCR meters and general