Battery charger with automatic change from current to voltage mode control
US4131841A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 19, 1976 |
| Grant date | Dec 26, 1978 |
| Priority date | — |
| Expiry date | Aug 19, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An improved battery charger having a current limiting transformer for supplying a charging current. The transformer includes primary and secondary coils wound about a core and has a shunt path for a portion of the magnetic flux induced by the voltage appearing on the primary. A pair of silicon controlled rectifiers are alternately triggered into their forward conductive states at points relatively early in each alternating current half cycle to provide a maximum charging current when a substantially discharged battery is to be recharged. As the charging process progresses, the battery voltage increases and at a predetermined value of the battery voltage a smooth transition from the current-controlled mode to a voltage-controlled mode is inaugurated. After the change to the voltage-controlled mode has been completed, the SCRs are triggered into conduction much later in each cycle, thereby furnishing a very low or trickle current which can be continued indefinitely without damage to the battery. Simple adjustments are provided for determining the maximum current charging rate and the particular voltage at which the changeover is to begin. Provision is also made for preventing an init…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.