Position transmitter and method for determining a position of a rotating shaft

Position transmitter system for determining a position of a shaft that can rotate, having an AMR sensor unit or a GMR sensor unit, whereby the sensor unit is configured as a two-part AMR sensor or a two-part GMR sensor, or the sensor unit has two AMR sensors or GMR sensors, in which only a magnet (9) disposed on a shaft (10) to be monitored is provided for detecting the position,

• wherein the sensor unit (1) is used for detecting the 360° angle position and at the same time for detecting the complete revolutions and that the position data are derived exclusively from the signals of the AMR sensor unit or the GMR sensor unit, and that a microcontroller that is activated only during the measurement times is provided, and that a waking device (16) controlled by the magnet (9) is provided, for waking the microcontroller (14), and that the waking device (16) has at least one transducer (33, 34) triggered by the magnetic field of the magnet (9);
• wherein the magnet comprises a diametrically magnetized magnet corresponding to the sensor unit, the sensor unit comprises an AMR sensor unit having a two-part AMR sensor or two AMR sensors having two output signals, and the position transmitter comprises a microcontroller, said microcontroller and said sensor unit evaluating a magnetic field of the magnet;
• wherein the microcontroller comprises an active microcontroller only during measurement times, said microcontroller comprising an alarm clock device controlled by the magnet for waking up the microcontroller;
• wherein the alarm clock device has at least one signal transmitter triggered by the magnetic field of the magnet;
• wherein the at least one signal transmitter comprises a reed switch;
• and
• wherein the position transmitter system has a closed housing, the sensor unit being disposed in the closed housing, and the magnet being disposed in or on the shaft to be monitored, lying opposite the sensor unit, outside of the housing;
• wherein there is a magnet carrier that can be adapted to the shaft to be monitored;
• wherein the magnet carrier is disposed outside of the housing (2) without contact;
• and
• said contact free mounting of said magnet (9) outside of said housing (2 permits selecting a variable axial distance (A) between said sensor (6) and said magnet (9), and said contact free mounting permits a longitudinal axis of said magnet (9) to vary a radial distance (B) from a longitudinal axis of said sensor unit 16).