| 摘要 |
A versatile linear self-excited bridge primarily intended for the measurement or comparison of very low capacitance values. The differential input of the device makes it suitable in a variety of other applications such as, tachometers, gap or position indicators, null detectors, transducers, etc. The inputs of a pair matched bipolar transistors which exhibit negative resistance characteristics are connected to a common inductor which completes an oscillatory loop. The ratio of the DC potentials at the collectors of the two transistors are directly related in their respective emitter capacitors, and hence when, these capacitors are equal in value, the output of a differential amplifier having inputs which are connected to the collectors of the two transistors is zero.
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