| 摘要 |
A transducer for sensing the angular position of a shaft over a limited angle (e.g., +/-30 DEG ) uses a printed circuit board mounted perpendicular to the shaft between capacitor plates of a bifurcated vane clamped to the shaft. The board has two pairs of symmetrical capacitor plates, one pair on each side with each plate of a pair located symmetrically with respect to the midposition of the vane plates, and corresponding plates of each pair connected together at a junction to place the two corresponding variable capacitors in parallel. Circuitry produces a Mark-Space signal proportional to the position of the bifurcated vane. Using the total Mark-Space period to continually derive a midposition reference, and comparing that midposition reference to any deviation of equal Mark and Space periods provides a position signal proportional to deviation from midposition of the bifurcated vane. By offsetting the midposition reference signal, the position output signal will be proportional to the position of the plates of the bifurcated vane with respect to the circuit board plates from one extreme to the other.
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