Patent ID: 9564772
Date: 2017-02-07
CPC Classifications: H02J

Claim:
1. A charger, comprising: an input, at least one switch having a first node coupled to a reference voltage, a current sensor coupled between the input and a second node of the at least one switch, an output coupled to a third node of the at least one switch, and a charge controller coupled to the input and configured to determine an input voltage, coupled to the current sensor and configured to determine an input current, and coupled to control inputs of the at least one switch, the at least one switch responsive to control signals supplied by the charge controller to the control inputs thereof to control voltage and current at the output of the charger, the charge controller configured to produce the control signals in response to the input voltage and the input current in a manner that approximately maximizes electrical power drawn at the input by causing the electrical power drawn at the input to dither around a maximum value of the electrical power drawn at the input by causing one of the input voltage and the input current to change in a direction, comparing a post-change value of the electrical power drawn at the input to a pre-change value of the electrical power drawn at the input, causing the one of the input voltage and the input current to change again in the direction if the post-change value is greater than the pre-change value, and causing the one of the input voltage and the input current to change in an opposite direction if the post-change value is less than the pre-change value.