| 摘要 |
A capacitive sensor, in particular a pressure sensor, is illustrated and described, having a measurement capacitor (1) which has a variable capacitance, specifically a pressure-dependent capacitance, having a reference capacitor (2) - which possibly has a variable capacitance, in particular a pressure-dependent capacitance - having a drive circuit (3) which drives the measurement capacitor (1) and the reference capacitor (2), and having an evaluation circuit (4) which evaluates the voltages which are present on the measurement capacitor (1) and on the reference capacitor (2) and emits a sensor signal which is, in particular, pressure dependent, the drive circuit (3) having: a first constant current source (5) which charges the measurement capacitor (1), a second constant current source (6) which charges the reference capacitor (2), a first discharge path (7) which is connected in parallel with the measurement capacitor (1), discharges the measurement capacitor (1) and is switchable, and a second discharge path (8) which is connected in parallel with the reference capacitor (2), discharges the reference capacitor (2) and is switchable. The capacitive sensor according to the invention ensures a constantly high measurement accuracy irrespective of external influences, in particular irrespective of temperature fluctuations, to be precise in that a control circuit (9) is provided, in that the drive circuit (3), controlled by the control circuit (9), at least partially charges the measurement capacitor (1) and the reference capacitor (2) at the same time, and in that the evaluation circuit (4) ... by the control circuit (9) ... Original abstract incomplete.
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