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 Laboratory (ORNL), Oak Ridge, TN (United States)
- OSTI Identifier:
- 5844390
- Application Number:
- ON: DE85011643
- Assignee:
- Dept. of Energy
- 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, Jr, W H. Capacitance measuring device. United States: N. p., 1984.
Web.
Andrews, Jr, W H. Capacitance measuring device. United States.
Andrews, Jr, W H. Wed .
"Capacitance measuring device". United States.
@article{osti_5844390,
title = {Capacitance measuring device},
author = {Andrews, Jr, W H},
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}
}