Piezoresistive transducer.

摘要

The invention relates to a transducer comprising a resistance bridge 10 having at least one arm 22, 26 formed by a piezoresistive element arranged on a flexible substrate of which at least the surface is not electrically conductive. A voltage is applied across one diagonal of the bridge 10 and an integrator 12 integrates the out of balance voltage of the bridge. The integral is compared by a comparator 16 with a reference signal derived from the voltage applied across the diagonal of the bridge 10 and provides an output of two inverters 30, 32 for reversing the polarity of the applied voltage when the said threshold is crossed. The frequency of reversal of the applied voltage, which is dependent upon the deflection of the substrate is supplied as an output signal.