Capacitive reading device for a pointer instrument
AssigneeSiemens Aktiengesellschaft
InventorStefan Klehr
Life of this patent
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Abstract
A capacitive reading device for a pointer instrument, wherein n radial electrodes alternating with radial counter electrodes are arranged opposite the pointer instrument in an arc to capacitively detect the position of a rotating pointer of the pointer instrument, where the counter electrodes are electrically connected to one another and connected to a first measurement connection of a capacitance digital converter, the n electrodes are connected to a second measurement connection of the capacitance digital converter via an n×k connection matrix and a downstream 1-of-k multiplexer, the n×k connection matrix connects each of the n electrodes to in each case one of k channels of the 1-of-k multiplexer, the connection pattern varies along the arc with n variations of b from k, and where n>k≥b>1.
Claims8
A capacitive reading device for a pointer instrument, comprising
- a support for arrangement opposite to a rotating pointer of the pointer instrument;
- a plurality of n radial electrodes alternating with radial counter electrodes arranged in an arc on the support;
- and
- a capacitance digital converter;
- wherein the radial counter electrodes are electrically connected to one another and are attached to a first measurement interface of the capacitance digital converter;
- wherein the n radial electrodes are attached via an n×k connection matrix and via a downstream 1-of-k multiplexer to a second measurement interface of the capacitance digital converter;
- and
- wherein the n×k connection matrix connects each of the n radial electrodes to a respective k channel of k channels of the 1-of-k multiplexer, a connection pattern along the arc varying to permit determination of a position of the pointer.
Dependencies are inferred from the claim text.