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:
Feb. 13, 1990
Filed:
Dec. 09, 1988
Daho Taguezout, Lausanne, CH;
Mai T Xuan, Chavannes, CH;
Asulab S.A., Bienne, CH;
Abstract
A barrel spring winding device comprises a solar cell (3) arranged to receive ambient light, a capacitor (4) connected to the terminals of the cell, a stepping motor (6) and a control circuit (5). The input of the circuit is connected to the terminals of the capacitor and its output to the terminals of the motor. The rotor of the motor is operatively connected to wind a barrel spring, for example of a watch. The cell (3) charges the capacitor (4) and when the voltage thereof, measured by a differential amplifier (23), reaches a reference voltage (V.sub.r), the capacitor is connected to the terminals of the motor by a switching transistor (27). Discharge of the capacitor supplies to the motor a drive pulse whose duration is determined by a one-shot flip-flop (25). After the pulse, the capacitor is once again charged by the cell. To prevent the motor from receiving a drive pulse before it has stopped, i.e. in the event of intense lighting of the cell, another one-shot flip-flop (29) inhibits control of the switching transistor (27) during a period of time corresponding to the time needed for the rotor to make one complete step.