Magnetic absolute angular position sensor for valves controlled by electric part-turn actuators
AssigneeBiffi Italia S.R.L.
InventorsArchimede Affaticati, Giordano Alfieri
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Abstract
The invention finds application in the field of electric valve actuators. Particularly, the invention relates to a magnetic absolute angular position sensor for valves controlled by electric part-turn actuators, wherein the rotation α of the valve shaft (10) induces a change in the direction along which the lines of the magnetic field generated by a magnet (8) integral therewith, pass through a stationary circuit board (7), containing two Wheatstone bridges arranged at 45° to each other, and made of a magneto-resistive material. Hence, two 90° electric signals X and Y are generated, having the same amplitude, which allow to uniquely determine the angle of rotation α of the shaft (10).
Claims5
A magnetic absolute angular position sensor for valves controlled by electric part-turn actuators, which is formed by an essentially cylindrical case 1, closed by a cover 3, in which a support disk (2) is located, containing a magnet (8) and a circuit board (7) in front of the latter, characterized in that a rotation α of the valve shaft (10) induces a change in the direction of the magnetic flux lines generated by the magnet (8), which is arranged to be integral with the valve shaft (10) through the support disk (2), and generates two electric signals X and Y in the circuit board (7), which are offset at an angle of 90°, i.e. a sinusoidal signal and a cosinusoidal signal, which are both proportional to twice the angle of rotation α, allowing to uniquely determine the angle of rotation of the valve, which may be a value of up to 120°.
Dependencies are inferred from the claim text.