Nxp B.v.

Koninklijke Philips Corporation N.v.

Thomas Stork

Stefan Butzmann

Michael Hinz

Jacobus Adrianus Van Oevelen

Hendrik Boezen

Reinhard Buchhold

Marcus Weser

Stefan Pusch

Winand Van Sloten

Gunnar Schulz

A phase detection system () comprises an input terminal (), first and second peak detectors (), an averaging unit (), an offset unit (), and a comparator (). Input terminal () is coupled to the first and to the second peak detectors () and provides an input signal to phase detection system (). Averaging unit () is coupled between offset unit () and both the first peak detector and the second peak detector (), and generates an intermediate signal. Offset unit () is coupled to input terminal () and generates two comparable signals by applying a predetermined offset in signal strength to the input signal or the intermediate signal. The comparator () is coupled to the offset unit () and generates an output signal by comparing the two comparable signals which is indicative of the phase of the input signal.

Phase detector system

A sensor () has an output coupled to a first comparator input. A control circuit () is arranged to switch from an upward tracking mode to a downward relative level detection mode, to a downward tracking mode, to an upward relative level detection mode and back to the upward tracking mode successively. A first and second digital to analog conversion circuit () receive a first and second digital control value from the control circuit () respectively. A controllable combiner circuit () has inputs coupled to outputs of the first and second digital to analog conversion circuits () and an output coupled to the second comparator input, the control circuit () having first output coupled to controllable combiner circuit () to cause the combiner circuit () to supply first and second combiner output signals determined by the first and second digital to analog conversion circuit () to the second comparator input in the upward and downward tracking mode respectively, and to supply a third combiner output signal corresponding to an average of the first and second combiner output signals to the second comparator input in the relative level detection modes. The control circuit () has an input coupled to the output of the comparator (), the control circuit () controlling one directional upward tracking by the first digital to analog conversion circuit () of upward changes of the sensing signal in the upward tracking mode, and controlling one directional downward tracking by the second digital to analog conversion circuit () Of downward changes of the sensing signal in the upward tracking mode.

Electronic sensing circuit that compensates for reference voltage drift

What is described is a configuration for determining the position of a body along a movement direction, wherein the body is in the form of a magnetized encoder with two magnetic tracks extending, on one surface of the body, along the movement direction, at least essentially in parallel with one another, wherein, at specified intervals along the movement direction, a first of the magnetic tracks exhibits magnetized sections in which the magnetic north poles are aligned so as to be at least largely coincident in a magnetization direction that is essentially at right-angles to the surface of the body, and wherein, at intervals specified to coincide with the above-mentioned intervals along the movement coordinate, the second of the magnetic tracks exhibits magnetized sections in which the magnetic south poles are aligned so as to be at least largely coincident in the said magnetization direction, and wherein, in each case, a magnetized section of one of the magnetic tracks is located at least largely centrally in relation to a gap between two magnetized sections of the other magnetic track, with a magnetoresistive sensor, in the form of an angle sensor, which is arranged above the magnetic tracks, for determining the directions of magnetic fields brought about by the magnetized sections of the magnetic tracks in an area extending along the movement coordinate, essentially in parallel with the surface of the body. By virtue of the invention, a simple configuration for the precise determination of the position of a body along a movement direction is created, wherein this configuration does not necessarily have to be affixed centrally upstream of the head of the body.

Angular displacement encoder with two magnetic tracks

Growing community of inventors

Hamburg, Germany

Thomas Stork