Sensor arrangement and method

Patent metadata

Field	Value
Publication number	US-9423482-B2
Application number	US-201314064082-A
Country	US
Kind code	B2
Filing date	Oct 25, 2013
Priority date	Apr 27, 2011
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

A sensor arrangement has a current regulator, a reference resistance a feed current scaler and a sensor element having an internal resistance, the internal resistance of the sensor element and the reference resistance having a predetermined ratio. The current regulator is implemented to provide a reference current by the reference resistance and to change the reference current in response to an interference influence-conditioned change of the reference resistance such that the voltage decreasing across the reference resistance remains in a predetermined range around an applied set voltage. The current regulator is implemented to provide a feed current to the feed current scaler and to change a magnitude of the feed current depending on a magnitude of the reference current. The feed current scaler is implemented to feed a scaled feed current into the sensor element to scale a voltage according to the scaling of the feed current.

First claim

The invention claimed is:

1. A sensor arrangement, comprising:
a current regulator;
a reference resistance;
a feed current scaler; and
a sensor element comprising an internal resistance, wherein the internal resistance of the sensor element and the reference resistance comprise a predetermined ratio with respect to each other;
wherein the current regulator is implemented to provide a reference current by the reference resistance and, in response to an interference influence-conditioned change of the reference resistance, change the reference current such that the voltage decreasing across the reference resistance remains in a predetermined range around an applied set voltage;
wherein the current regulator is further implemented to provide a feed current to the feed current scaler and to change a magnitude of the feed current depending on a magnitude of the reference current; and
wherein the feed current scaler is implemented, based on the feed current, to supply a scaled feed current into the sensor element to scale a voltage decreasing across the internal resistance of the sensor element according to the scaling of the feed current.

2. The sensor arrangement according to claim 1 ,
wherein the current regulator is implemented to change the magnitude of the feed current proportional to the magnitude of the reference current in a ratio which results from the ratio between the reference resistance and the internal resistance of the sensor element and from a ratio between the set voltage and a voltage across the internal resistance decreasing with no or a minimum scaling of the feed current.

3. The sensor arrangement according to claim 1 ,
wherein the reference resistance is implemented such that certain interference influences which cause changes of the internal resistance of the sensor element change the magnitude of the reference resistance in a corresponding ratio so that the voltage decreasing across the internal resistance of the sensor element is independent of these interference influences within a tolerance range.

4. The sensor arrangement according to claim 1 ,
wherein the current regulator and the reference resistance are implemented to execute the change of the feed current such that with the interference influence-conditioned change of the reference resistance and an accompanying interference influence-conditioned change of the internal resistance of the sensor element the voltage decreasing across the internal resistance remains in a predetermined range.

5. The sensor arrangement according to claim 1 ,
which is implemented to generate the voltage decreasing across the internal resistance of the sensor element such that the same counteracts an offset proportion in an output signal of the sensor arrangement.

6. The sensor arrangement according to claim 1 ,
wherein a material of the reference resistance and a material of the internal resistance within a tolerance range comprise the same performance with respect to an interference influence such that a change of the reference resistance caused by an interference influence causes a unidirectional change of the internal resistance of the sensor element scaled according to the ratio between the reference resistance and the internal resistance of the sensor element.

7. The sensor arrangement according to claim 1 ,
wherein dimensions of the reference resistance scale with dimensions of the internal resistance of the sensor element according to the ratio between the reference resistance and the internal resistance of the sensor element.

8. The sensor arrangement according to claim 1 ,
wherein the reference resistance is implemented so that its resistance value experiences a temperature-conditioned change of the internal resistance of the sensor element according to the ratio between the reference resistance and the internal resistance of the sensor element.

9. The sensor arrangement according to claim 1 ,
further comprising a temperature-stable reference voltage source for generating the set voltage and wherein the current regulator is implemented to regulate the reference current such that the voltage across the reference resistance corresponds to the set voltage within a predetermined tolerance range.

10. The sensor arrangement according to claim 1 ,
wherein the current regulator comprises a regulating amplifier and a current provider;
wherein the regulating amplifier is implemented to provide a differential signal which describes a deviation of the voltage decreasing across the reference resistance from the set voltage; and
wherein the current provider is implemented, based on the differential signal, to provide the reference current and the supply current such that the supply current is proportional to the reference current.

11. A sensor arrangement, comprising:
a voltage regulator;
a feed current scaler; and
a sensor element comprising an internal resistance;
wherein the voltage regulator is implemented to set a supply voltage for the sensor element and, in response to an interference influence-conditioned change of the internal resistance of the sensor element, to change a supply current of the sensor element such that the supply voltage for the sensor element remains in a predetermined range;
wherein the voltage regulator is further implemented to provide a feed current to the feed current scaler and to change this feed current depending on the change of the supply current for the sensor element; and
wherein the feed current scaler is implemented, based on the feed current, to supply a scaled feed current into the sensor element, to scale a voltage decreasing across the internal resistance of the sensor element according to the scaling of the feed current.

12. The sensor arrangement according to claim 11 ,
wherein the voltage regulator is implemented to set the feed current such that a change of the feed current within a tolerance range is proportional to a change of the supply current.

13. The sensor arrangement according to claim 11 ,
wherein the voltage regulator is a foot-point regulator and is implemented to provide a foot-point voltage at the sensor element to change, in response to the change of the internal resistance of the sensor element, the supply current of the same such that the foot-point voltage remains in a predetermined range and to set the feed current proportional to the supply current within a tolerance range.

14. The sensor arrangement according to claim 13 ,
further comprising a feeding regulator which is implemented to provide a sensor voltage at the sensor element and which acts as a current source for the supply current;
wherein the foot-point regulator acts as a current sink for the supply current;
wherein the supply voltage corresponds to a difference between the sensor voltage and the foot-point voltage;
wherein the foot-point regulator and the feeding regulator, when changing the internal resistance of the sensor element, change the supply current in cooperation such that the supply voltage for the sensor element remains in the predetermined range; and
wherein the foot-point regulator is implemented to set the feed current depending on the supply current and to transfer changes of the supply current to the feed current.

15. The sensor arrangement according to claim 11 ,
wherein the voltage regulator is a feeding regulator and is implemented to provide a sensor voltage at the sensor element to change, in response to the change of the internal resistance of the sensor element, the supply current of the same so that the sensor voltage remains in a predetermined range and to set the feed c

Assignees

• Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E V

Inventors

• Herzer Elmar
• Schlag Ulrich
• Sauerer Josef

Classifications

• G01D3/028 Primary

  mitigating undesired influences, e.g. temperature, pressure · CPC title

• G01R35/005 Primary

  Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references (G01R33/0035, G01R35/002 take precedence) · CPC title