Patent · US Expired

Demodulation circuit for AC motor current spectral analysis

US4978909A · kind A · utility

35Cited by
8References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateAug 31, 1989
Grant dateDec 18, 1990
Priority date
Expiry dateAug 31, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R23/16
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in combination along with a frequency analyzer to produce improved spectral analysis of load-induced frequencies present in the electric current flowing in a motor-driven system.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.