Self-calibrating linear voltage differential transformer demodulator

• US 10,132,663 B2
• Filed: 04/30/2015
• Issued: 11/20/2018
• Est. Priority Date: 04/30/2015
• Status: Active Grant

• Current Assignee: Global Engineering Center - India (IDC), Goodrich Aerospace Services Private Limited
• Original Assignee: Goodrich Aerospace Services Private Limited, Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Ronning, Eric Duane, Ninjuri, Natraj, Rao, Kalluri
• Primary Examiner(s): Phan, Huy Q
• Assistant Examiner(s): Russo, Raul Rios
• Application Number:
  US14/700,582
• Publication Number:
  US 20160320217A1
• Time in Patent Office: 1,300 Days
• Field of Search: 324 51, 324 55, 324 74, 324130, 324200, 324202
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: G01D 5/20 by varying inductance, e.g. by a movable armature
• CPC Class Codes: G01D 5/2291 Linear or rotary variable differential transformers (LVDTs/RVDTs) having a single primary coil and two secondary coils
• CPC Class Codes: G01R 33/0017 Means for compensating offset magnetic fields or the magnetic flux to be measured; Means for generating calibration magnetic fields
• CPC Class Codes: G01R 33/0035 Calibration of single magnetic sensors, e.g. integrated calibration
• CPC Class Codes: G05B 2219/37124 Magnetic sensor
• CPC Class Codes: G05B 2219/37185 Magnetic ring and sensor

Abstract

A calibration system includes an excitation module that introduces an excitation signal to a primary coil of a differential transformer, a measurement module that measures, at a first phase shift, a positive value of an induced signal. The induced signal is caused by the excitation signal on a secondary coil of the differential transformer. The system further includes a calculation module that compares the positive value to a last positive value to form a compared positive value, and a calibration module that changes the first phase shift based on the compared positive value.

Claims

1. A differential transformer comprising:

a primary winding;

first and secondary windings;

a moveable shaft disposed between the primary winding and the first and second secondary windings;

a measurement module that measures voltages on the first and second secondary windings;

an excitation module that introduces an excitation signal to the primary winding, the excitation signal having a positive peak and a negative peak and induces a first signal on the first winding and induces a second signal on the second secondary winding, the excitation module generating a first enable pulse based on the positive peak that causes the measurement module to measure a voltage on the first second winding; and

a calibration module that shifts the first enable pulse by a first phase shift until a peak value of the first signal is found to form a phase shifted first enable pulse;

wherein, the excitation module generates the phase shifted first enable pulse to cause the measurement module to measure the induced signal in the first secondary winding.

2. The system of claim 1, a calculation module that determines a peak-to-peak value of the first signal based on the measurement of first signal when the measurement module received the phase shifter first enable pulse.