The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 1981
Filed:
Mar. 12, 1979
Richard G Sparber, Wheaton, IL (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
An impedance/admittance measuring circuit generates an output signal which is representative of the real or imaginary part of the impedance or admittance of a connected load. An excitation signal comprising a square wave having a fixed magnitude is generated and applied to a load. The response signal resulting from the excitation signal is filtered by a two pole bandpass filter (106). The filter output signal is used to control the excitation signal generator (101, 102) such that an oscillatory feedback loop is formed. By controlling the load connection and the phase relations between the excitation signal and the filter output signal, the magnitude of the output signal is representative of the real or imaginary part of the impedance or admittance of the connected load (103).