Patent ID: 7560902

Claim:
A battery charger apparatus comprising, an AC input, a voltage circuit including a plurality of switches through which power is supplied to a charger output for suppling power to charge a battery in response to switching of the plurality of switches, a duty cycle controller for producing duty cycle signals for controlling switching of said plurality of switches while maintaining a high power factor at the AC input, the duty cycle controller including: a plurality of current command signal generators including a plurality of signal inputs that receive a plurality of signals representing a plurality of operating conditions of the charger and a battery being charged and a plurality of current command outputs; a processor that generates a plurality of current command signals at said plurality of current command outputs in response to the plurality of signals representing the plurality of operating conditions; a selector that compares the plurality of current command signals from said current command outputs and selects a current command signal having only a lowest value and produces a lowest current command signal output in response thereto; and a duty cycle signal generator having a lowest current command signal input, a battery current signal input, a battery voltage signal input, an AC voltage waveform input, an AC current waveform input and a duty cycle signal output, said duty cycle signal generator producing the duty cycle signals at said duty cycle signal output in response to said lowest current command signal, a battery voltage signal (V BATT ), a battery current signal (I BATT ), an AC voltage waveform signal (V AC ) and an AC current waveform signal (I AC ).