Patent ID: 9219430
Filing Date: 2015-12-22
Classification: G01D,H02N

Abstract:
1. A sensor comprising a piezoelectric detector ( 10 ) mounted in a support having electrically conductive walls forming a first electrical potential reference, referred to as mechanical ground (MM), to which the piezoelectric detector ( 10 ) is connected, and a circuit for processing the signal delivered by the piezoelectric detector, said processing circuit comprising: an electrical supply circuit defining a second potential reference, referred to as electronic ground (ME), a charge amplifier comprising an operational amplifier, referred to as a processing amplifier ( an input ( an output ( a capacitive feedback loop ( wherein the capacitive feedback loop ( 16 ) comprises, between said output ( 15 ) of the processing amplifier ( 12 ) and said capacitor ( 29 ), a voltage adder circuit ( 61 , 64 , 66 , 67 , 68 , 69 ) adapted to add on the second terminal ( 72 ) of said capacitor ( 29 ) an electrical voltage which varies as a function of the potential difference between the mechanical ground (MM) and the electronic ground (ME), so that the variations of this potential difference are continuously compensated for at the input ( 13 ) of the processing amplifier ( 12 ) receiving the signal delivered by the piezoelectric detector ( 10 ).