| 摘要 |
A capacitive sensing circuit and system includes a variable capacitance sensing element as an active element in a circuit to measure changes in capacitance of the sensing element. A switching network in alternate cycles energizes a capacitor to develop a charge which effectively linearizes the sensor's capacitance response. In a push-pull circuit with two active sensing elements, a multi-channel switching network energizes two fixed correction capacitors to provide third or higher order correction, significantly extending the effective scale of the sensor. In a preferred embodiment, a single feedback signal is applied to all capacitors in different switching cycles. Examples include weight and pressure sensing systems.
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