Patent · US Expired

Method and apparatus for making diagnosis of electrolytic capacitor in operation

US5880589A · kind A · utility

9Cited by
3References
12Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 6, 1997
Grant dateMar 9, 1999
Priority date
Expiry dateMar 6, 2017

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG01R31/64
  • WIPO fieldMeasurement
  • WIPO sectorInstruments

Abstract

A charged voltage between the ground and a positive pole of backup capacitor 5 and a ground-casing voltage developed between the ground and a casing of capacitor 5 are determined. When the ground-casing voltage is smaller than a first value, it is judged that capacitor 5 has an opened circuit on its positive pole side; when the ground-casing voltage is larger than a second value, it is judged that capacitor 5 has an opened circuit on its negative pole side. A difference between the ground-casing voltage and the charged voltage is divided by the ground casing voltage so that a coefficient is obtained. When the coefficient is outside a predetermined range of values, it is judged that capacitor 5 is poor in capacitance, which makes it possible to determine, even in operation, whether capacitor 5 functions properly.

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