The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 22, 1981
Filed:
May. 08, 1979
Hubert Portmann, Colombier, CH;
Ebauches SA, Neuchatel, CH;
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.