LITHIUM-ION CELL CHARGING CIRCUIT WITH CURRENT-LIMITING TRANSFORMER AND LINEAR INTEGRATED CIRCUIT

摘要

A charging circuit and method for charging alithiumion cell or battery at a charging voltage that is varied duringthe charging of the cell or battery from a predetermined minimumcharging voltage to a predetermined maximum charging voltage.The charging circuit. includes a transformer for transforming linevoltage applied to the primary winding thereof to a lower ACsecondary winding voltage, the transformer being selected tolimit secondary winding output current when the charging voltageis not less than the predetermined minimum charging voltage toa value not exceeding a selected upper limit for the lithium-ioncell; a rectifier sab-circuit connected to the secondary windingof the transformer for rectifying the secondary winding voltage;and a charge-voltage regulator sub-circuit connected to therectifier sub-circuit for receiving the rectified secondarywinding voltage and providing an output charging voltage that islimited to the predetermined maximum charging voltage.