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Title: Digital ac monitor

Abstract

An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.

Inventors:
;
Issue Date:
OSTI Identifier:
7255125
Patent Number(s):
4672555 A
Application Number:
PPN: US 6-662392
Assignee:
Massachusetts Inst. of Tech., Cambridge, MA (United States) PTO; EDB-94-125330
DOE Contract Number:  
AC02-76ET20279
Resource Type:
Patent
Resource Relation:
Patent File Date: 18 Oct 1984
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; ELECTRONIC CIRCUITS; MONITORING; ALTERNATING CURRENT; ANALOG-TO-DIGITAL CONVERTERS; COMPUTER CALCULATIONS; DATA PROCESSING; CURRENTS; ELECTRIC CURRENTS; ELECTRONIC EQUIPMENT; EQUIPMENT; PROCESSING; 426000* - Engineering- Components, Electron Devices & Circuits- (1990-)

Citation Formats

Hart, G.W., and Kern, E.C. Jr. Digital ac monitor. United States: N. p., 1987. Web.
Hart, G.W., & Kern, E.C. Jr. Digital ac monitor. United States.
Hart, G.W., and Kern, E.C. Jr. Tue . "Digital ac monitor". United States.
@article{osti_7255125,
title = {Digital ac monitor},
author = {Hart, G.W. and Kern, E.C. Jr.},
abstractNote = {An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer. 24 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {6}
}