Meter reading sensor using TMR and hall effect sensors

Patent metadata

Field	Value
Publication number	US-10690519-B2
Application number	US-201815903127-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Feb 23, 2018
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

A system may include a dial wheel having a first magnet located at a first orbital position of the dial wheel and a second magnet located at a second orbital position of the dial wheel. A polarity of the first magnet at a surface of the dial wheel is opposite a polarity of the second magnet at the surface of the dial wheel. A sensor board includes a first magnetic sensor for sensing a magnetic field and is configured so that the first and second magnets cause the first magnetic sensor to generate an output pulse for each rotation of the dial wheel. The pulsed output is indicative of a volume of resource consumed.

First claim

What is claimed is:

1. A pulse sensor, comprising:
a dial wheel having a first magnet located at a first orbital position of the dial wheel, a second magnet located at a second orbital position of the dial wheel, and a third magnet located on a center axis of the dial wheel, wherein the first magnet comprises a north pole and a south pole and the second magnet comprises a north pole and a south pole and wherein the first magnet and the second magnet are located perpendicular to the center axis of the dial wheel;
a first magnetic sensor for sensing a magnetic field, wherein the first magnetic sensor is positioned so that during a rotation of the dial wheel, when the dial wheel is in a first position the north pole of the first magnet is aligned with the first magnetic sensor and when the dial wheel is in a second position the south pole of the second magnet is aligned with first magnetic sensor; and
the first magnetic sensor configured to generate a pulsed output for each rotation of the dial wheel, wherein
when the dial wheel is in a first position, the pulsed output is a first value;
as the dial wheel rotates from the first position to the second position, the pulsed output remains at the first value until the magnetic field sensed by the first magnetic sensor reaches a second threshold value;
once the magnetic field reaches the second threshold value, the pulsed output switches to a second value and remains at the second value until the dial wheel rotates to the second position;
as the dial wheel rotates from the second position to the first position, the pulsed output remains at the second value until the magnetic field sensed by the first magnetic sensor reaches a first threshold value;
once the magnetic field reaches the first threshold value, the pulsed output switches to the first value; and
a second magnetic sensor positioned in alignment with the center axis of the dial wheel so that the second magnetic sensor is aligned with the third magnet, and wherein the second magnetic sensor is configured to sense a magnetic field along the center axis and to generate a second output proportional to the magnetic field, the second magnetic sensor is configured to detect a first error condition based on the magnetic field falling below a first threshold and a second error condition based on the magnetic field rising above a second threshold.

2. The pulse sensor of claim 1 , wherein a polarity of a first magnetic field value sensed by the first magnetic sensor when the dial wheel is in the first position is opposite a polarity of a second magnetic field value sensed by the first magnetic sensor when the dial wheel is in the second position.

3. The pulse sensor of claim 1 , wherein the first magnetic sensor is one of (i) an integrated digital device with latch mode or (ii) an analog device that can output a voltage indicative of a magnetic field in combination with additional circuitry configured to implement a latch function.

4. The pulse sensor of claim 1 , wherein the first magnetic sensor generates the pulsed output based on detecting that the magnetic field has passed a threshold based on a first hysteresis of the first magnetic sensor.

5. The pulse sensor of claim 1 , wherein the first magnetic sensor is a bipolar Hall effect sensor, and wherein the bipolar Hall effect sensor configured to operate in a latch mode.

6. The pulse sensor of claim 4 , wherein the pulsed output switching from the second value to the first value indicates that one unit of measure is consumed.

7. A pulse sensor, comprising:
a dial wheel having a magnet located at a first orbital position of the dial wheel, wherein the magnet comprises a north pole and a south pole and wherein the magnet is located in an orbital position with the north pole and the south pole located perpendicular to an axis of the dial wheel;
a sensor board including a magnetic sensor for sensing a magnetic field, wherein the sensor board is positioned so that during a rotation of the dial wheel relative to the sensor board when the dial wheel is in a first position the north pole of the magnet is aligned with the magnetic sensor and when the dial wheel is in a second position the south pole of the magnet is aligned with magnetic sensor;
the magnetic sensor configured to generate a pulsed output for each rotation of the dial wheel, wherein
when the dial wheel is in a first position, the pulsed output is a first value,
as the dial wheel rotates from the first position to the second position, the pulsed output remains at the first value until the magnetic field sensed by the magnetic sensor reaches a second threshold value;
once the magnetic field reaches the second threshold value, the pulsed output switches to a second value and remains at the second value until the dial wheel rotates to the second position;
as the dial wheel rotates from the second position to the first position, the pulsed output remains at the second value until the magnetic field sensed by the magnetic sensor reaches a first threshold value; and
once the magnetic field reaches the first threshold value, the pulsed output switches to the first value.

8. The pulse sensor of claim 7 , wherein a polarity of a first magnetic field value sensed by the magnetic sensor when the dial wheel is in the first position is opposite a polarity of a second magnetic field value sensed by the magnetic sensor when the dial wheel is in the second position.

9. The pulse sensor of claim 7 , wherein the magnetic sensor is a Hall effect sensor, and wherein the Hall effect sensor is configured to either (i) operate in a latch mode or (ii) generate a latch in conjunction with a latching circuit.

10. The pulse sensor of claim 7 , wherein the magnetic sensor generates the pulsed output based on detecting that the magnetic field has passed a threshold based on a hysteresis of the magnetic sensor.

11. The pulse sensor of claim 7 , wherein the pulsed output switching from the second value to the first value indicates that one unit of measure is consumed.

12. The pulse sensor of claim 7 , further comprising:
an additional magnet located at a center of the dial wheel; and
an additional magnetic sensor, wherein the sensor board is positioned so that the additional magnetic sensor is aligned with the additional magnet, and wherein the additional magnet sensor is configured to generate an additional output proportional to an additional received magnetic field, wherein
the additional magnetic sensor is configured to detect an error condition based on the additional received magnetic field falling below a first threshold or the additional received magnetic field rising above a second threshold.

13. A pulse sensor, comprising:
a dial wheel having a first magnet located at a first orbital position of the dial wheel and a second magnet located at a second orbital position of the dial wheel, wherein a polarity of the first magnet at an edge of the dial wheel is opposite a polarity of the second magnet at the edge of the dial wheel;
a first magnetic sensor for sensing a magnetic field, wherein the first magnetic sensor is positioned outside and adjacent to a circumference of the dial wheel, wherein the first magnetic sensor is positioned so that during a rotation of the dial wheel relative to the first magnetic sensor when the dial wheel is in a first position the first magnet is aligned with the first magnetic sensor;
a second magnetic sensor for sensing a magnetic field, wherein the second magnetic sensor is positioned outside and adjacent to the circumference of the dial wheel and at a position located ninety degrees around the dial wheel from the first magnetic senso

Assignees

• Landis & Gyr Innovations Inc

Inventors

• Lee Tou
• Prakash Vidya

Classifications

• Y04S20/30

  Smart metering, e.g. specially adapted for remote reading · CPC title

• G01D4/002 Primary

  Remote reading of utility meters · CPC title

• G01D4/008

  Modifications to installed utility meters to enable remote reading · CPC title

• G01D5/24457 Primary

  Failure detection · CPC title

• G01D5/145

  influenced by the relative movement between the Hall device and magnetic fields (see G01R33/06) · CPC title