SENSORE MAGNETICO RESISTIVO PER FORNIRE SEGNALI ELETTRICI

A sensor 13, comprising at least two directional magnetic sensitive elements 14 with sensitive axes at 90 DEG to each other on a common substrate, is moved relative to a permanent magnet 11 in the homogeneous magnetic field (H) of the latter. Depending on the rotational movement, a sinusoidal voltage variation of a frequency equal to the frequency of the rotational movement is generated in the sensor (13). Furthermore, several sensors (13) may also be used, which are arranged with a certain angle of rotation ( beta ) with respect to each other in such a way that a precisely defined phase relationship ( phi ) is established in the signal voltages of the sensors. In this way, additional pulses can be induced by suitable combination of the signal voltages with the aid of an evaluation circuit (71). Furthermore, it is also possible to detect several movement operations and positions simultaneously and independently of one another. The elements 14 may be magnetoresistors, Hall devices, magnetodiodes or transistors, or inductively operated elements.