Device for charging an accumulator from an electrical energy source more particularly for an electronic watch
US4291266A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 8, 1979 |
| Grant date | Sep 22, 1981 |
| Priority date | — |
| Expiry date | May 8, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/906
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to an electronic device for charging an accumulator from an electric energy source, more particularly one or more solar cells, intended in particular for an electronic wristwatch. The device represents the equivalent of an ideal diode inserted between the source of electrical energy and the battery. A solar cell (1) feeds a charging current to the accumulator (2) via a transistor (3) and, if desired, a diode (7) in parallel with the transistor (3). The conduction state of the transistor (3) is monitored by a differential amplifier (4) which has an off-set voltage (U.sub.off), the value and polarity of which are determined by a generator (5). This off-set voltage (U.sub.off) defines the voltage drop between the energy source and the accumulator (2) which is selected to be between 20 and 50 millivolts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.