Linear displacement position detector - has encapsulated magnetoresistive sensor element in electromagnetically screened chamber with bar magnet activation

摘要

The linear displacement position detector has a sensor element (23) which possesses a ferromagnetic magnetoresistive surface of predetermined pattern formed by a comb-shaped matrix of e.g. nickel-iron encapsulated in synthetic resin and mounted on a ceramic circuit board (24) in an electromagnetically screened chamber (26). A rectangular bar magnet (22) with end poles is attached to a slider (21) and operating stem (21a) and moves against the compression spring (29) so that its flux interacts with the matrix. The resultant change in output voltage from the sensor (23) at the terminal (28) is amplified and displayed as a measure of stem (21a) movement. ADVANTAGE - Provides improved linearity of response over a larger measurement range. Screening ensures measurements are not influenced by external electromagnetic fields and presence of other metal.