Devices and methods for smart sensor application

Patent metadata

Field	Value
Publication number	US-11656269-B2
Application number	US-202117463103-A
Country	US
Kind code	B2
Filing date	Aug 31, 2021
Priority date	Jan 9, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

An apparatus comprises a load resistance connectable in series with the electronic sensor to form a series resistance of the load resistance and the internal impedance of the electronic sensor; an excitation circuit configured to apply a predetermined voltage to a circuit element; and a measurement circuit configured to: initiate applying the predetermined voltage to the series resistance and determining the series resistance; initiate applying the predetermined voltage to the load resistance and determining the load resistance; and calculate the internal impedance of the sensor using the determined series resistance and the load resistance, and provide the calculated internal impedance to a user or process.

First claim

What is claimed is:

1. A test circuit for an electronic sensor, the test circuit comprising:
a load resistance connectable in series with the electronic sensor to form a series resistance of the load resistance and an internal impedance of the electronic sensor;
an excitation circuit configured to apply a predetermined voltage to a circuit element; and
a measurement circuit configured to:
initiate applying the predetermined voltage to the series resistance and determining the series resistance;
initiate applying the predetermined voltage to the load resistance and determining the load resistance; and
calculate the internal impedance of the electronic sensor using a difference of the determined series resistance and the load resistance, and provide the calculated internal impedance to a user or process.

2. The test circuit of claim 1 , wherein the excitation circuit is configured to apply a specified electrical signal having a signal amplitude less than twenty millivolts (20 m V) to the series resistance, and the internal impedance of the electronic sensor is less than ten ohms (10Ω).

3. The test circuit of claim 1 , wherein the electronic sensor is an electro-chemical sensor.

4. The test circuit of claim 1 , wherein the measurement circuit is configured to calibrate the predetermined voltage applied using the excitation circuit.

5. The test circuit of claim 1 , wherein the test circuit is configured to:
connect a calibration resistor of a predetermined resistance to an output of the test circuit;
adjust an excitation signal applied by the excitation circuit until the test circuit measures a specified current corresponding to the predetermined voltage; and
apply the predetermined voltage to the series resistance and the load resistance.

6. A method of monitoring an electronic sensor using a test circuit, the method comprising:
connecting a load resistance in series with the electronic sensor to form a series resistance of the load resistance and an internal impedance of the electronic sensor;
applying, using a measurement circuit, a predetermined voltage to the series resistance and determining the series resistance;
applying the predetermined voltage to the load resistance and determining the load resistance;
calculating the internal impedance of the electronic sensor using a difference of the determined series resistance and the load resistance; and
providing the calculated internal impedance to a user or process.

7. The method of claim 6 ,
wherein the applying the predetermined voltage includes applying a specified electrical signal having a signal amplitude less than twenty millivolts (20 m V) to the series resistance; and
wherein calculating the internal impedance of the electronic sensor includes calculating an internal impedance less than ten ohms (10Ω).

8. The method of claim 6 , wherein calculating the internal impedance of the electronic sensor includes calculating the internal impedance of an electro-chemical sensor.

9. The method of claim 6 , including calibrating the predetermined voltage.

10. The method of claim 9 , wherein calibrating the predetermined voltage includes:
electrically connecting, by the test circuit, a calibration resistor of a predetermined resistance to outputs of the test circuit;
adjusting, by the test circuit, an excitation signal until a specified current is measured corresponding to the predetermined voltage of the excitation signal; and
applying the predetermined voltage to the series resistance and the load resistance.

11. An integrated circuit comprising:
a sensor circuit having an impedance;
a load resistor connectable in series with the sensor circuit to form a series resistance of the load resistor and the internal impedance of the sensor circuit;
an excitation circuit configured to apply a predetermined voltage to a circuit element; and
a measurement circuit configured to:
initiate applying the predetermined voltage to the series resistance and determining the series resistance;
initiate applying the predetermined voltage to the load resistor and determining load resistance of the load resistor; and
calculate the impedance of the sensor circuit using a difference of the determined series resistance and the load resistance.

12. The integrated circuit of claim 11 , wherein the excitation circuit is configured to apply a specified electrical signal having a signal amplitude less than twenty millivolts (20 m V) to the series resistance, and the impedance of the sensor circuit is less than ten ohms (10Ω).

13. The integrated circuit of claim 11 , wherein the sensor circuit includes an electro-chemical sensor.

14. The integrated circuit of claim 11 , wherein the measurement circuit is configured to calibrate the predetermined voltage applied using the excitation circuit.

15. The integrated circuit of claim 11 , including:
a calibration resistor;
wherein the excitation circuit is configured to apply an excitation signal to the calibration resistor;
wherein the measurement circuit is configured to:
adjust the excitation signal applied to the calibration resistor until a specified current corresponding to the predetermined voltage is measured; and
initiate applying the predetermined voltage to the series resistance and the load resistance.

Assignees

• Analog Devices International Unlimited Co

Inventors

• Qu GuangYang
• Liu Yincai Tony
• Hao Baotian
• Wang Hanqing
• Mei Hengfang
• Luo Rengui
• Zhao Yimiao
• Ding Junbiao

Classifications

• G01N27/122

  Circuits particularly adapted therefor, e.g. linearising circuits · CPC title

• G01R35/00

  Testing or calibrating of apparatus covered by the other groups of this subclass · CPC title

• G01N33/0057

  Warfare agents or explosives · CPC title

• G01N27/417

  using cells {, i.e. more than one cell} and probes with solid electrolytes · CPC title

• G01R31/2829 Primary

  Testing of circuits in sensor or actuator systems (testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844) · CPC title