| 摘要 |
A magnetic angle encoder comprises a digit runner(2001), permanent magnets (100, 300) coaxially mounted with the digit runner, a tunnel magnetic-resistance angular-displacement sensor (500), and a digit processing circuit. In the encoder, the tunnel magnetic-resistance angular-displacement sensor is located in a region within detection planes (120, 320) of the permanent magnets (100, 300) at a distance of a specific radius range from an axis of a columnar-ring of the permanent magnets (100, 300), and within the region of the specific radius range, the rotating magnetic field phase angle (Φ) of a component of a magnetic field generated by the permanent magnets (100, 300) in the detection planes (120, 320) present a linear variation relationship with a rotation phase angle (α) of the permanent magnets. Also disclosed is an electronic water meter, comprising a plurality of counting units and a digit processing circuit. The counting units further comprise a digit counting runner (2001), permanent magnets (100, 300) and a tunnel magnetic-resistance angular-displacement sensor (500). The digit processing circuit is connected to each tunnel magnetic-resistance angular-displacement sensor, and converts the output of the tunnel magnetic-resistance angular-displacement sensor into a digital readout. The magnetic angle encoder and the electronic water meter have the advantages of small a volume and high measurement accuracy. |
