US 5,652,501 A · Voltage sensor for detecting cell voltages

Abstract

A battery charger/monitor circuit for charging and/or monitoring a plurality of series-connected cells, including a voltage sensor for sensing the voltage across each of the cells to provide a high cell voltage signal proportional to the highest voltage across any of the cells and a low cell voltage signal proportional to the lowest voltage across any of the cells. The circuit is operable in a monitor mode or a charge mode. In the monitor mode, the cells are disconnected from a load if the low cell voltage signal decreases to a first predetermined level. The circuit includes a controller which provides a control signal in response to the high cell voltage signal, the low cell voltage signal and a current sense signal, for controlling the charging of the cells. In the charge mode, the cells receive a constant charge current until the high cell voltage signal reaches a second predetermined level, after which the voltage across the cell charged to the highest voltage is held substantially constant, causing the charge current to be reduced.

Claims9

Dependent claims

A voltage sensor for sensing the voltage across each of a plurality of series-connected cells, said voltage sensor comprising:

a plurality of differential amplifiers, each one having a pair of input terminals coupled across a corresponding one of said plurality of cells and an output terminal;
and
a network coupled to said output terminals of said plurality of differential amplifiers for providing a high cell voltage signal proportional to a relative highest voltage across one of said plurality of cells and a low cell voltage signal proportional to a relative lowest voltage across one of said plurality of cells.

Dependencies are inferred from the claim text.

Voltage sensor for detecting cell voltages

Life of this patent

Voltage sensor for detecting cell voltages

Life of this patent

Abstract

Claims9