Signal conditioning in a position sensing system

Patent metadata

Field	Value
Publication number	US-12372381-B2
Application number	US-202217988297-A
Country	US
Kind code	B2
Filing date	Nov 16, 2022
Priority date	Sep 19, 2022
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A position sensing system includes a linear variable differential transformer (LVDT) to provide a first output voltage and a second output voltage. The position sensing system also includes two precision rectifiers. Each of the precision rectifiers comprises only operational amplifiers and resistors and obtains the first output voltage or the second output voltage as an input and to provide a full-wave rectified output.

First claim

What is claimed is:

1. A position sensing system comprising:
a linear variable differential transformer (LVDT) configured to provide a first output voltage and a second output voltage; and
two precision rectifiers, each of the precision rectifiers comprising only operational amplifiers and resistors and being configured to obtain the first output voltage or the second output voltage as an input and to provide a full-wave rectified output;
wherein each of the precision rectifiers includes a first operational amplifier, a second operational amplifier, and a third operational amplifier.

2. The position sensing system according to claim 1 , wherein, based on the input being a negative half cycle of the first output voltage or the second output voltage, the first operational amplifier is configured to output a first half-wave rectified sine wave and the second operational amplifier is configured to output 0 volts.

3. The position sensing system according to claim 2 , wherein the first operational amplifier is an inverting operational amplifier, and the input is provided to an inverting input of the first operational amplifier.

4. The position sensing system according to claim 2 , wherein, based on the input being a positive half cycle of the first output voltage or the second output voltage, the first operational amplifier is configured to output 0 volts and the second operational amplifier is configured to output a second half-wave rectified sine wave.

5. The position sensing system according to claim 4 , wherein the second operational amplifier is a voltage follower, and the input is provided to a non-inverting input of the second operational amplifier.

6. The position sensing system according to claim 4 , wherein the third operational amplifier is configured to combine the first half-wave rectified sine wave and the second half-wave rectified sine wave to provide the full-wave rectified output.

7. The position sensing system according to claim 1 , wherein the LVDT includes a primary winding, a first secondary winding, and a second secondary winding, the first output voltage is output by the first secondary winding, and the second output voltage is output by the second secondary winding.

8. The position sensing system according to claim 7 , wherein the LVDT also includes a magnetic core connected to a moving part whose position is sensed by the position sensing system.

9. The position sensing system according to claim 1 , further comprising a processor configured to obtain the position based on the full-wave rectified output provided by the two precision rectifiers.

10. A method of assembling a position sensing system, the method comprising:
connecting a linear variable differential transformer (LVDT) to a moving part whose position is sensed by the position sensing system and arranging the LVDT to provide a first output voltage and a second output voltage; and
arranging two precision rectifiers such that each of the two precision rectifiers obtains either the first output voltage or the second output voltage as an input and provides a full-wave rectified output, and each of the precision rectifiers comprises only operational amplifiers and resistors;
wherein arranging each of the precision rectifiers includes arranging a first operational amplifier, a second operational amplifier, and a third operational amplifier.

11. The method according to claim 10 , wherein the arranging the first operational amplifier and the second operational amplifier includes the first operational amplifier outputting a first half-wave rectified sine wave and the second operation al amplifier outputting 0 volts based on the input being a negative half cycle of the first output voltage or the second output voltage.

12. The method according to claim 11 , wherein the first operational amplifier is an inverting operational amplifier, and the arranging the first operational amplifier includes providing the input to an inverting input of the first operational amplifier.

13. The method according to claim 11 , wherein the arranging the first operational amplifier and the second operational amplifier includes the first operational amplifier outputting 0 volts and the second operational amplifier outputting a second half-wave rectified sine wave based on the input being a positive half cycle of the first output voltage or the second output voltage.

14. The method according to claim 13 , wherein the second operational amplifier is a voltage follower, and the arranging the second operational amplifier includes providing the input to a non-inverting input of the second operational amplifier.

15. The method according to claim 13 , wherein the arranging the third operational amplifier includes the third operational amplifier combining the first half-wave rectified sine wave and the second half-wave rectified sine wave to provide the full-wave rectified output.

16. The method according to claim 10 , wherein the LVDT includes a primary winding, a first secondary winding, and a second secondary winding, and the arranging the LVDT includes arranging the first secondary winding to provide the first output voltage and arranging the second secondary winding to provide the second output voltage.

17. The method according to claim 16 , wherein the connecting the LVDT to the moving part includes connecting a magnetic core of the LVDT to the moving part.

18. The method according to claim 10 , further comprising configuring a processor to obtain the position based on the full-wave rectified output provided by the two precision rectifiers.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Kumar Dhananjay
• Sreedhar Swathika

Classifications

• G01B7/003

  for measuring position, not involving coordinate determination (coordinate measuring G01B7/004) · CPC title

• G01D5/2266

  specially adapted circuits therefor · CPC title

• G01D5/2291 Primary

  Linear or rotary variable differential transformers (LVDTs/RVDTs) having a single primary coil and two secondary coils · CPC title