US 2006/0250166 A1 · Voltage to current to voltage cell voltage monitor (VIV)

Abstract

A voltage measurement circuit is provided which converts a voltage of a first voltage source connected in series with an offset voltage source to an output voltage, including first and second current mirrors for accurately measuring voltage so as to provide a proportional output voltage with the offset voltage removed. Further, voltage measurements can be precisely determined for each of a plurality of voltage sources, such as a plurality of electrochemical cells in a series electrical connection. By virtue of the voltage measurement circuit, the effect of different offset voltage values on the measured voltage is minimized. Also, the voltage measurement circuit exhibits enhanced stability to variations in operating temperature. Accordingly, accuracy of voltage measurements where offset voltages are present is improved.

Claims19

Dependent claims

A voltage measurement circuit for converting a voltage of a first voltage source connected in series with an offset voltage source to an output voltage, comprising:

a first resistor connected to a first terminal of the first voltage source;
a first transistor and a second transistor connected as a first current mirror, wherein the first transistor is connected to a second terminal of the first voltage source and the second transistor is connected to the first resistor;
a third transistor and a fourth transistor connected as a second current mirror, wherein the third transistor is connected to the first transistor, and the fourth transistor is connected to the second transistor;
a fifth transistor connected to the fourth transistor;
a second resistor connected between the third transistor and a reference potential;
and
a third resistor connected between the fifth transistor and the reference potential,
wherein an output voltage formed by a current flowing through the third resistor is proportional to the voltage of the first voltage source.

5 more elements

A voltage measurement circuit for converting voltages of a plurality of electrochemical cells connected in series to output voltages which are independent of offset voltage, comprising:

a plurality of electrochemical cells connected in series;
for each electrochemical cell, a measurement module which comprises:
a first resistor connected to a first terminal of an electrochemical cell;
a first transistor and a second transistor connected as a first current mirror, wherein the first transistor is connected to a second terminal of the first voltage source and the second transistor is connected to the first resistor;
a third transistor and a fourth transistor connected as a second current mirror, wherein the third transistor is connected to the first transistor, and the fourth transistor is connected to the second transistor;
a fifth transistor connected to the fourth transistor;
a second resistor connected between the third transistor and a reference potential;
and
a third resistor connected between the fifth transistor and the reference potential,
wherein an output voltage formed by a current flowing through the third resistor is proportional to the voltage of the electrochemical cell.

7 more elements

Dependencies are inferred from the claim text.

Voltage to current to voltage cell voltage monitor (VIV)

Life of this patent

Voltage to current to voltage cell voltage monitor (VIV)

Life of this patent

Abstract

Claims19