Patent ID: 7804273
Filing Date: 2010-09-28
Classification: H02J,Y02T

Abstract:
1. A selector circuit to select among a DC power source and a plurality of batteries for an electronic device, said selector circuit comprising: a first comparator configured to compare a first input signal representative of a voltage level of said DC power source with a first threshold level and provide a first output signal representative of a difference between said first input signal and said first threshold level; a selector output circuit configured to provide selector output signals that control selection among said DC power source and said plurality of batteries, said selector output circuit providing said selector output signals to select said DC source and deselect said plurality of batteries if said first output signal is representative of said voltage level of said DC power source being greater than said first threshold level; a second comparator configured to compare said first input signal with a second threshold level and provide a second output signal representative of a difference between said first input signal and said second threshold level, said second threshold level greater than said first threshold level; a charge enable circuit configured to accept at least said second output signal and provide a charge enable signal in response to at least said second output signal, said charge enable signal enabling charging of at least one of said plurality of batteries if, at least, said second output signal is representative of said voltage level of said DC power source being greater than said second threshold level.