Patent ID: 6940274

Claim:
A magnetic position detecting device in which a magnet is mounted on one of a fixed body and a moving body, and a magnetism-sensitive element is mounted on the other of said fixed body and said moving body and a position of said moving body to said fixed body is detected based on a change of a magnetic flux density that said magnetism-sensitive element senses, the improvement being characterized in that an S-pole and an N-pole of the magnet are juxtaposed along a direction in which said magnet and said magnetism-sensitive element move relatively to each other, and said magnetic position detecting device comprises: a reference signal generating circuit for generating a reference signal for detecting a position at which said magnetism-sensitive element senses a zero magnetic flux density; a comparing circuit for comparing a detect signal generated from an output signal of said magnetism-sensitive element, with said reference signal, and for producing a reference position detect signal of a predetermined level when said detect signal and said reference signal are equal in level; and a comparing signal control circuit for controlling said detect signal or said reference signal to be input to said comparing circuit so that said reference position detect signal of a predetermined level is output only during a fixed period while said magnet and said magnetism-sensitive element mutually approach.