Patent ID: 9086300
Filing Date: 2015-07-21
Classification: G01D

Abstract:
1. An electric motor having a rotor and a stator as well as a measuring device designed for detecting a position of the rotor, which is movable relative to the stator, and comprising a sensor system for the provision of sensor signals in dependence on the position of the rotor relative to the stator and a processing device for controlling the sensor system, for processing the sensor signals and for outputting a position signal, wherein the processing device is configured for switching between a first operating state with a continuous or high-frequency intermittent provision of supply energy to the sensor system and a second operating state with a low-frequency intermittent provision of supply energy to the sensor system, wherein the processing device comprises a first circuit block and a second circuit block, the first circuit block being configured to switch the second circuit block between an activation state and a deactivation state, and wherein the sensor system comprises a motion sensor configured to provide a signal if the rotor moves relative to the stator while the voltage supply for the electric motor is disconnected, and wherein the first circuit block of the processing device is configured to evaluate the signal provided by the motion sensor and to output a motion signal to the second circuit block when the signal provided by the motion sensor exceeds a presettable threshold value, the motion signal switching the second circuit block from the deactivation state to the activation state, the second circuit block providing the sensor system with supply energy when switched to the activation state.