Reluctance effective die magnetometric sensor

摘要

PURPOSE:To enable the holding of effective sensitivity even in a high temperature range free from temperature changes by arranging a pair of magnetoresistance effect elements with one end thereof earthed and the other end thereof connected to a constant current circuit to output a potential difference between the elements. CONSTITUTION:A pair of magnetoresistance effect elements 2a and 2b are arranged in parallel and each one end thereof is earthed while each other end thereof connected to a constant current circuit 3 to detect an output V from a potential difference between the elements 2a and 2b. Here, magnetoresistance effectiveness S of the elements 2a and 2b decreases with a rise in temperature and an intrinsic resistance p increases with a rise in temperature. Hence, a relation of Ks -Kp is established between a decrease rate Ks and an increase Kp. Therefore, a change p (t) in resistance due to the magnetoresistance effectiveness at a temperature (t) equals a product between the resistance p and the effectiveness S and so, is in no way affected by temperature. Thus, an output V as given by V = p i (i: constant current value) is compensated for a decrease in the effectiveness S as caused by a temperature rise thereby allowing the obtaining of an effective output even in an atmosphere of a high temperature free from temperature.