Patent ID: 7036791
Filing Date: 2006-05-02
Classification: F02D,F05C,G01D,Y10T

Abstract:
1. A method for contactless detection of a position of a butterfly valve shaft of a butterfly valve connecting piece, the butterfly valve connecting piece having a housing which can be closed off by a lid and a throttle orifice which is arranged in the housing, for a butterfly valve which is arranged on the butterfly valve shaft, the butterfly valve shaft being capable of being driven by an electric actuator drive and having, at one of its ends, a magnet which is arranged in contactless alignment with a sensor which is arranged on the lid, said method comprising the steps of: providing the sensor with a first magnetoresistive sensor element and a second magnetoresistive sensor element, generating an approximately sinusoidal signal in the first magnetoresistive sensor element and an approximately cosinusoidal signal in the second magnetoresistive sensor element by means of the magnet when there is rotational movement of the butterfly valve shaft, feeding the first approximately sinusoidal signal and the second approximately cosinusoidal signal to evaluation electronics arranged in the sensor, generating an approximately arctan-shaped signal in the evaluation electronics from the approximately sinusoidal signal of the first magnetoresistive sensor element and the approximately cosinusoidal signal of the second magnetoresistive sensor element, generating a control signal as a function of the approximately arctan-shaped signal in a control unit arranged outside the housing, and feeding the control signal to the actuator drive arranged in the butterfly valve connecting piece in order to adjust the butterfly valve shaft.