Practical and simple circuitry for the measurement of small capacitance

D. Y. Lin, J. D. Wu, Y. J. Chang, J. S. Wu

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Practical and cost-effective circuitry with high sensitivity has been developed to measure a small capacitance using current compensation method. The circuitry uses an electronic switch to periodically connect or separate the capacitor under test (Cx) from a reference capacitor (Cr). When Cx is connected in parallel with Cr the total capacitance becomes Cx + Cr. On the other hand, as Cx is separated from Cr, the total capacitance is only Cr. This periodic change of the capacitance generates a periodic square-wave output with an amplitude in proportion to the capacitance of Cx. A high sensitivity of ΔVΔC= 202.2 mVpF has been achieved, making the circuitry a powerful tool in measuring small capacitances. Three applications have been performed to present its capability: (a) displacement, (b) height of liquid, and (c) angle of tilt. The experimental results demonstrate the performance of the circuitry.

Original languageEnglish
Article number014703
JournalReview of Scientific Instruments
Volume78
Issue number1
DOIs
Publication statusPublished - 2007 Apr 8

All Science Journal Classification (ASJC) codes

  • Instrumentation

Fingerprint Dive into the research topics of 'Practical and simple circuitry for the measurement of small capacitance'. Together they form a unique fingerprint.

  • Cite this