| 摘要 |
These capacities measuring transducer, particularly for capacities of low value, comprises two parallel bridge branches connected to an oscillator and comprising each at least a capacitor; additionally, it comprises a differential amplifier of which the input is connected to the bridge branches and of which the output is connected retroactively with one of the bridge branches. For the balancing of such a measurement transducer of which the reaction circuit comprises only passive elements in one bridge branch, a circuit element (D<u1>u, D<u2>u) is series connected with each of the bridge branches, and to the second bridge branch is applied a fixed potential (e<u1>u) for a potential determined by the differential amplifier (OA<u1>u) and therein inversely with respect to the output of the differential amplifier. Thereby the stability and the linearity between the capacity and the output voltage are considerably improved. |
