hello , i search a charge amplifier schematics with Op amp to interface a piezo transducer (force sensor).If you can give me a little help, thanks in advance for your answers.
charge amplifier are basically three parts (not counting power supply): an operational amplifier, a capacitor and a resistor. For a charge amplifier, the usual voltage integrator circuit is modified in two aspects:
1. The input resistor Ri is omitted and the current source (piezo sensor) coupled directly to the inverting input.
2. An high ohmic resistor is connected in parallel to Co for integrator automatic auto-zero.