Encoding techniques for a capacitance-based sensor

Apparatus, comprising:

• a sensor face including several tracks spaced apart from one another, a designated one of the tracks including a first electrode and a second electrode spaced apart from one another by an electrically nonconductive gap;
• a detection device spaced apart from the tracks and extending across the tracks to receive signals by capacitive coupling to one or more of the tracks;
• and
• sensor circuitry electrically coupled to the tracks and the detection device, the circuitry being structured to generate a first number of bits from a sequential signal pattern detected with the detection device in response to a changing voltage applied to different ones of the tracks in accordance with an established sequence, the circuitry being further structured to generate a second number of bits as a function of a first signal and a second signal, the first signal being detected with the detection device capacitively coupled to the first electrode and being generated in response to a first voltage waveform, the second signal being detected with the detection device capacitively coupled to the second electrode and being generated in response to a second voltage waveform, the first bits and the second bits representing a sensed position of the detection device along the tracks with the first bits being more significant than the second bits.

Apparatus, comprising:

• means for encoding a first number of bits each corresponding to a different one of a number of sensor tracks carried on a sensor face, the encoding means including a detection device positioned opposite the sensor face to extend across the tracks and spaced apart from the sensor face, the detection device including an electrode;
• means for applying a first voltage waveform to a first electrode segment of a designated one of the tracks and a second voltage waveform to a second electrode segment of the designated one of the tracks, the first segment and a second segment being spaced apart from one another by an electrically nonconductive gap;
• means for capacitively coupling the electrode to the first segment to provide a first signal in response to the first waveform and a second signal in response to the second waveform;
• and
• means for determining a second number of bits as a function of the first signal and the second signal with the sensor device, the first bits and the second bits representing sensed position with the first bits being more significant than the second bits.

Apparatus, comprising:

• a first shaft;
• a second shaft;
• a torsion member coupling the first shaft and the second shaft together;
• a first rotor fixed to the first shaft to turn therewith, the first rotor including a first face with a first electrode and a second electrode separated by an electrically nonconductive gap;
• a second rotor fixed to the second shaft to turn therewith, the second rotor including a second face positioned opposite and spaced apart from the first face, the second face including a third electrode;
• and
• sensor circuitry coupled to the first electrode, the second electrode, and the third electrode, the circuitry being structured to provide a voltage waveform sequence to the first electrode and the second electrode including at least one signal that is an inverse of another signal, and process a signal sequence detected by capacitive coupling of the third electrode with the first electrode and the second electrode to determine position of the third electrode relative to the first face.