Current-to-voltage transition control of a battery charger
US6166521A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2000 |
| Grant date | Dec 26, 2000 |
| Priority date | — |
| Expiry date | Apr 17, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J7/342
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit is provided to minimize the charging cycle time of a battery charging system by maximizing the length of time that high constant charging current is applied to a discharged battery. The control circuit includes a constant current (CC) error amplifier, a constant voltage (CV) error amplifier, an output amplifier, and two pole-splitting compensation networks. The control circuit works in conjunction with a power source to charge a secondary battery. The pole-splitting compensation networks allow the CC, CV, and output amplifiers to be configured for high gain, without sacrificing output stability. The control circuit provides a sharp transition between the CC mode and CV mode of operation. In the CC mode, fast bulk battery charging is provided. In the CV mode, the control circuit initially provides a "top-off" charge to the battery and subsequently safely maintains the battery at its fully charged state. By using bi-directional transconductance error amplifiers as the CC and CV error amplifiers, the control circuit can be optimized for pole-splitting compensation. The control circuit can be operated with a constant internal reference voltage or a variable internal r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.