Battery state-of-charge indicator
US4234840A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1979 |
| Grant date | Nov 18, 1980 |
| Priority date | — |
| Expiry date | Apr 13, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/21
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for indicating the charge state of a battery supplying discharge current to its load circuit under actual load operation during which battery discharge current is subject to magnitude variations and interruptions, having means for storing a stored signal whose value is representative of battery state-of-charge, means for rapidly increasing the value of the stored signal to the scaled value of the battery terminal voltage when its scaled value is below that of the battery terminal voltage, first means for decreasing the value of the stored signal at a slow rate preestablished such that the stored signal decreases from a first value representative of a fully charged battery to a second value representative of a discharged battery in a time period approximating the average time required during normal operation of the load circuit for the fully charged battery to become discharged, and second means, operative only during intervals when the battery supplies no discharge current to the load, for decreasing the value of the stored signal at a rate intermediate said slow and fast rates and related to the difference between the scaled values of the battery terminal voltage and the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.