Method and apparatus for electrically exciting a m

专利名称：Method and apparatus for electrically

exciting a magneto-resistor device

发明人：Kalyan P. Gokhale,Thaddeus Schroeder申请号：US08/002370申请日：19930106公开号：US05404102A公开日：19950404

摘要：A method and apparatus for electrically exciting a magneto- resistor (MR)device that is adapted to sense variations in a magnetic field. Electric current is deliveredto flow through the MR device and produce a voltage drop across the resistance the MRdevice, where the voltage drop varies in accordance with changes in the flux density ofthe sensed magnetic field. The current flowing through the MR device is limited to apredetermined maximum current value to prevent damage to the MR device due to selfheating at elevated operating temperatures. When the delivered current is less than thepredetermined maximum current value, the current flowing through the MR device iscontrolled to maintain a measured characteristic of the voltage drop appearing acrossthe MR device at a desired value. This increases the sensitivity of the MR device over itsoperating temperature range to variations in the sensed magnetic field. In one

embodiment, the delivered current is controlled to maintain the peak voltage appearingacross the resistance of the MR device at a desired peak value. In another embodiment,the delivered current is controlled to maintain the average voltage appearing across theMR device at a desired average value.

申请人：GENERAL MOTORS CORPORATION

代理人：Timothy G. Gorbatoff

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