skip to main content
DOE Patents title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Capacitance measuring device

Abstract

A capacitance measuring circuit is provided in which an unknown capacitance is measured by comparing the charge stored in the unknown capacitor with that stored in a known capacitance. Equal and opposite voltages are repetitively simultaneously switched onto the capacitors through an electronic switch driven by a pulse generator to charge the capacitors during the ''on'' portion of the cycle. The stored charge is compared by summing discharge currents flowing through matched resistors at the input of a current sensor during the ''off'' portion of the switching cycle. The net current measured is thus proportional to the difference in value of the two capacitances. The circuit is capable of providing much needed accuracy and stability to a great variety of capacitance-based measurement devices at a relatively low cost.

Inventors:
Issue Date:
Research Org.:
Oak Ridge National Lab., TN (USA)
OSTI Identifier:
5844390
Application Number:
ON: DE85011643
Assignee:
Dept. of Energy EDB-85-087914
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; CAPACITANCE; MEASURING INSTRUMENTS; DESIGN; ELECTRICAL PROPERTIES; PHYSICAL PROPERTIES; 440300* - Miscellaneous Instruments- (-1989)

Citation Formats

Andrews, W.H. Jr. Capacitance measuring device. United States: N. p., 1984. Web.
Andrews, W.H. Jr. Capacitance measuring device. United States.
Andrews, W.H. Jr. Wed . "Capacitance measuring device". United States.
@article{osti_5844390,
title = {Capacitance measuring device},
author = {Andrews, W.H. Jr.},
abstractNote = {A capacitance measuring circuit is provided in which an unknown capacitance is measured by comparing the charge stored in the unknown capacitor with that stored in a known capacitance. Equal and opposite voltages are repetitively simultaneously switched onto the capacitors through an electronic switch driven by a pulse generator to charge the capacitors during the ''on'' portion of the cycle. The stored charge is compared by summing discharge currents flowing through matched resistors at the input of a current sensor during the ''off'' portion of the switching cycle. The net current measured is thus proportional to the difference in value of the two capacitances. The circuit is capable of providing much needed accuracy and stability to a great variety of capacitance-based measurement devices at a relatively low cost.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1984},
month = {8}
}