Method for inspecting capacitors
US6469516B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 17, 1999 |
| Grant date | Oct 22, 2002 |
| Priority date | — |
| Expiry date | Nov 17, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/64
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method for judging the conformity or non-conformity of a capacitor from the charging characteristic at the time when a direct-current voltage is applied to the capacitor, a threshold current value I0 of the dielectric polarization component of the capacitor is determined in advance, an evaluation function n(t) is determined based on a logarithmic value of the difference between the measured charging current value m(t) of the capacitor and the threshold current value I0 or the difference between their logarithmic values, and the evaluation function n(t) is approximated to a quadratic curve. When the quadratic coefficient of the quadratic approximation equation has a plus sign the capacitor is judged to be non-conforming, and when the coefficient has a minus sign, the capacitor is conforming.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.