Circuit arrangement for converting a resistance variation into a frequency variation

摘要

A simple circuit for converting the resistance variations of a strain gauge measuring bridge into a frequency variation of an oscillator. The circuit includes first and second phase shift circuits connected in cascade in a feedback loop with a frequency-independent device having a variable gain factor F connected in parallel with the first phase shift circuit. The first phase shift circuit includes a high pass filter and a summing amplifier and the second phase shift circuit includes an all-pass filter circuit.