| 摘要 |
PURPOSE:To perform stable detecting operation with high accuracy without reference to variation in ambient temperature by applying a ferromagnetic material magneto-resistance element with constant bias magnetic force at right angles to driving magnetic force. CONSTITUTION:A magnetic proximity switch which uses an MR element 1 is provided with a bias magnetic force source 4 which makes bias magnetic force Bb operate in a constant direction and this bias magnetic force source 4 is equalized in temperature characteristics to a driving magnetic force source 3; and the absolute value of the driving magnetic force Ba on the surface of the MR element 1 when the driving magnetic force source 3 is positioned at set operation distance, i.e. at a detection position is equalized to the absolute value of the bias magnetic force Bb and the threshold value v2 of a comparator 2 is set equal to the output voltage v1 of the MR element 1 when no external magnetic force operates. Consequently, the influence of temperature character-istics of the MR element 1 and both magnetic force sources 3 and 4 are not exerted at all, so extremely high detection accuracy and stable detecting operation can be obtained regardless of variation in ambient temperature.
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