Battery charger with automatic change from current to voltage mode control
US4019111A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 1975 |
| Grant date | Apr 19, 1977 |
| Priority date | — |
| Expiry date | May 14, 1995 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S320/28
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
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 initial sudden current surge when first turning on the power, thereby avoiding any unnecessary blowing of fuses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.