Temperature/voltage controlled battery charging circuit
US6707273B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 18, 2002 |
| Grant date | Mar 16, 2004 |
| Priority date | — |
| Expiry date | Jul 18, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02J7/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A battery charging circuit particularly adapted to recharging NiMh batteries utilizes a thermistor to develop a control voltage corresponding to the temperature of the battery being charged and compares such voltage to an accurately measured battery terminal voltage. At a preset condition of a combination of the two voltage readings, the charging circuit converts from charging at a relatively high and fast charging rate to a relatively slow rate corresponding to a trickle current passing around a SCR through which the fast charging current normally flows. The circuit components are selected such that the battery achieves a charge of substantially 95% capacity before switching to the relatively slow rate and enables display of a state of charge indicating that the 95% capacity charge has been achieved and without any “popping” or cyclic ON-OFF effect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.