CIRCUIT AND METHOD OF OPERATION FOR AN ELECTRICAL POWER SUPPLY
4 Assignments
0 Petitions
Accused Products
Abstract
A battery charging circuit comprising: a semiconductor switch having an output connected to a rechargeable battery; a battery charge controller for receiving 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 the quantity of current supplied to the rechargeable battery when the voltage drop is too great; whereby the total power dissipated by the battery charge controller is controlled, the portable device receiving the power it needs to operate and the rechargeable battery receiving any additional available power.
17 Citations
38 Claims
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1-19. -19. (canceled)
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20. A battery charging circuit comprising:
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a switch having an output connected to a rechargeable battery and configurable to isolate the rechargeable battery from a portable device; a battery charge controller configured to receive power from an external source and supply output power to the portable device; and a voltage sensing circuit configured to; measure the voltage drop across the battery charge controller; and respond to the voltage drop across the battery charge controller by modulating the switch to control the quantity of current supplied to the rechargeable battery such that the portable device receives a predetermined amount of power to operate and the rechargeable battery receives a reminder of the power available from the battery charge controller. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 31, 32, 33, 34, 35)
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29-1. The battery charging circuit of claim 29, wherein the external power supply comprises a computer data bus having a power node.
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36. A method for charging a battery of a portable device via an external power supply, the method comprising the steps of:
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connecting the input of a battery charge controller to the external power supply; connecting the output of the battery charge controller, in parallel, to the portable device and the input of a switch; connecting the output of the switch to the battery; controlling the current output of the battery charge controller; measuring a voltage drop across the battery charge controller; and responding to the voltage drop across the battery charge controller by modulating the switch to control the quantity of current supplied to the rechargeable battery such that the portable device receives a predetermined amount of power to operate and the rechargeable battery receives a reminder of the power available from the battery charge controller.
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37. A power supply circuit comprising:
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means for measuring the voltage drop across a battery charge controller providing power to a portable device and the input of a switch in parallel; means for controlling the current output of the battery charge controller; and means for responding to the voltage drop across the battery charge controller by modulating the switch to control the quantity of current supplied to the rechargeable battery such that the portable device receives a predetermined amount of power to operate and the rechargeable battery receives a reminder of the power available from the battery charge controller. - View Dependent Claims (38)
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Specification