| 摘要 |
PROBLEM TO BE SOLVED: To provide a position transducer which is easily installed in a small fluid pressure cylinder, small size, space saving and capable of gaining stable output for the variation of temperature. SOLUTION: In a small fluid pressure cylinder, a magnetic body 1 is arranged inside a coil 2 and inside a hollow piston rod 3 in the state the inductance of the coil 2 is increased, eddy current generates in the duplication part. By utilizing the decrease of magnetic flux penetrating the coil due to the eddy current and resulting decrease of the inductance of the coil 2, the transient response primarily generating in the relation between the inductance and resistance 4 of the coil 2 when a rectangular voltage with a constant period is impressed to the coil 2 and the resistor 4 connected in series is observed at both ends of the coil 2 or of the resistor 4. A position transducer is constituted to correlate the time to exceeding a threshold of a certain voltage with the position of the hollow part rod 3 and to detect and position of the piston rod 3.
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