CIRCUIT AND METHOD OF OPERATION FOR AN ELECTRICAL POWER SUPPLY

摘要

A battery charging circuit comprising: a semiconductor switch having an outp ut connected to a rechargeable battery; a battery charge controller for receivi ng power from an external source, and supplying output power to a portable device and the input of the semiconductor switch, the current output of the battery charge controller being controllable; and a voltage sensing circuit for: measuring the voltage drop across the battery charge controller; and responding to the voltage drop across the battery charge controller by modulating the semiconductor switch to reduce t he quantity of current supplied to the rechargeable battery when the voltage dr op is too great; whereby the total power dissipated by the battery charge controller i s controlled, the portable device receiving the power it needs to operate and the rechargeable battery receiving any additional available power.