Valve actuators having magnetic angle sensors
A valve actuator including a magnetic angle sensor is disclosed. The magnetic angle sensor may function as an absolute position encoder. The magnetic angle sensor may also function as an incremental position encoder. The magnetic angle sensor may generate angular velocity data. The magnetic angle sensor may be used in quarter-turn and single-turn rotary valve actuators. The magnetic angle sensor may also be used in multi-turn rotary and linear valve actuators.
1. A valve actuator, comprising:
at least one rotatable member; and
a magnetic angle sensor in communication with the at least one rotatable member, wherein the magnetic angle sensor comprises:
a single magnet having an axis of rotation substantially about a midpoint of the single magnet and in axial alignment with an axis of rotation of the at least one rotatable member; and
a sensor circuit holding two distinct arrays of Hall sensors, wherein the Hall sensors are radially arrayed, the sensor circuit is in alignment with the axis of rotation of the single magnet, and the sensor circuit is configured to be mounted on either side of a printed circuit board.
2. The valve actuator of claim 1 , wherein the magnetic angle sensor is configured to generate absolute position data.
3. The valve actuator of claim 1 , wherein the magnetic angle sensor is configured to generate incremental position data.
4. The valve actuator of claim 1 , wherein the single magnet rotates with the at least one rotatable member.
5. The valve actuator of claim 1 , wherein the sensor circuit comprises an array of magneto-resistive sensors.
6. The valve actuator of claim 1 , wherein the at least one rotatable member is configured for less than or equal to one revolution.
7. The valve actuator of claim 1 , wherein the at least one rotatable member is configured for multiple revolutions.
8. The valve actuator of claim 1 , wherein the magnetic angle sensor further comprises a second sensor circuit, wherein the second sensor circuit is in alignment with the axis of rotation of the single magnet.
9. A method of determining valve actuator position, the method comprising:
providing a magnetic angle sensor comprising:
a single magnet having an axis of rotation substantially about a midpoint of the single magnet and in axial alignment with an axis of rotation of at least one rotatable member;
a first sensor circuit attached to a first side of a printed circuit board, the first sensor circuit having an array of sensors; and
a second sensor circuit attached to a second side of the printed circuit board, the second side of the printed circuit board located opposite the first side, wherein each of the first sensor circuit and the second sensor circuit is in alignment with the axis of rotation of the single magnet, and each of the first sensor circuit and the second sensor circuit sense the position of the single magnet;
correlating an electrical output of the magnetic angle sensor installed in a valve actuator with a position of an output shaft of the valve actuator;
energizing the magnetic angle sensor to generate electrical output from the magnetic angle sensor; and
determining the position of the output shaft from the electrical output of the magnetic angle sensor.
10. The method according to claim 9 , wherein determining the position of the valve actuator comprises determining absolute position of the output shaft.
11. The method according to claim 9 , wherein determining the position of the valve actuator comprises determining incremental position of the output shaft.
12. The method according to claim 9 , further comprising determining an angular velocity of the output shaft.
13. A valve actuator, comprising:
at least one rotatable member; and
a magnetic angle sensor in communication with the at least one rotatable member, wherein the magnetic angle sensor comprises:
a single magnet having an axis of rotation substantially about a midpoint of the single magnet and in axial alignment with an axis of rotation of the at least one rotatable member; and
a first sensor circuit attached to a first side of a printed circuit board, the first side of the printed circuit board facing the magnet; and
a second sensor circuit attached to a second side of the printed circuit board, the second side of the printed circuit board facing away from the magnet, wherein each of the first sensor circuit and the second sensor circuit is in alignment with the axis of rotation of the single magnet, and each of the first sensor circuit and the second sensor circuit sense the position of the single magnet.
14. The valve actuator of claim 13 , wherein one of the first sensor circuit and the second sensor circuit comprises one or more Hall sensors.
15. The valve actuator of claim 14 , wherein the other of the first sensor circuit and the second sensor circuit comprises one or more magneto-resistive sensors.