| 摘要 |
PROBLEM TO BE SOLVED: To perform stable position detection even if a position detector is mounted on a fluid pressure cylinder so that the leading side of a lead wire thereof can be set either on a piston side or on a head side. SOLUTION: The position detector 10 comprises a circuit board 20 which is vertically arranged relative to a magnet 16 provided on a piston 12 in a mounted state on the fluid pressure cylinder 11, and two magnetic sensors 21 and 22 disposed on both surfaces of the circuit board 20 while being respectively shifted in the moving direction of the piston 12 so that the operating ranges thereof are partially overlapped. The magnetic sensors 21 and 22 each compare an output voltage of a magnetic resistance element showing a resistance value corresponding to the intensity of magnetic field from the magnet 16 with a reference voltage by a comparator and output the comparison result. The position detector 10 includes a light emitting diode which emits light when one of the two magnetic sensors 21 and 22 is in the detecting state, and a light emitting diode which emits light when both of the two magnetic sensors 21 and 22 are in the detecting state. COPYRIGHT: (C)2008,JPO&INPIT
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