Chen Hong Lee

US Patent:

43984266, Aug 16, 1983

Filed:

Jul 2, 1981

Appl. No.:

6/279938

Inventors:

Kyong Park - Chatsworth CA
Chen Y. Lee - Troy MI

Assignee:

Kavlico Corporation - Chatsworth CA

International Classification:

G01L 912

US Classification:

73724

Abstract:

A capacitive pressure transducer system includes a reference capacitor and a capacitor which varies with pressure; and circuitry which involves alternately charging one of the capacitors to a reference voltage level, and then switching to charge the other capacitor; and circuitry for producing an output voltage which varies as the duty cycles of the two capacitors shift; and the output is therefore substantially proportional to the pressure changes. Feedback is provided to incrementally change the capacitor charging and switching timing or duty cycles by changing the charging current or the reference voltage at which switching occurs, to substantially eliminate deviations from linearity in the voltage versus pressure characteristic.