Piezoelectric transducer

Claim 2

An instrument transducer comprising a housing, a piezoelectric device in the housing for producing an electrical signal when deformed from a normal condition thereof, means movable in response to a physical input to the transducer for deforming said device from its normal condition so that the device generates an electrical signal having a value indicative of the value of said input, active circuit means in the housing of such type to require energization thereof from externally of its housing coupled to said device for receiving generated signals from the device and for operating upon the generated signals in a predetermined manner to provide transducer output signals, and energization and transducer output signal connector terminal means carried by the housing and including only two terminal elements each of which is conductively connected to separate locations in said circuit means.

Claim 3

In combination with a transducer according to claim 3, a coaxial cable connected at one end thereof to the transducer connector terminal elements, a signal readout device coupled to the other end of the cable for receiving output signals from the transducer, and power supply means connected across the cable between the transducer housing and the readout device.

Claim 4

The combination according to claim 4 wherein the transducer circuit means has input terminals coupled across the piezoelectric device and output terminals coupled across the coaxial cable, the circuit means being arranged so that the voltage across the output terminals follows substantially a voltage applied across the input terminals thereof and so that the circuit means appears to define an open circuit between The input and output terminals thereof.

Claim 5

In a transducing device having a piezoelectric element mounted within a housing, the combination comprising an active circuit energized from externally of said housing for coupling the piezoelectric element to a low impedance coaxial line, the circuit including input terminal means and output terminal means, means for connecting the input terminal means to the piezoelectric element for supplying signals derived from the element to the circuit, the circuit being arranged so that a voltage at the output terminal means follows substantially the value of a signal applied to the input terminal means and so that the circuit appears to define an open circuit between the input and output terminal means, the circuit being mounted within the housing, and a two-terminal coaxial connector mounted on the housing and connected within the housing across the circuit output terminal means.

Claim 6

The combination according to claim 6 including a low impedance coaxial line connected to said connector at one end thereof, and a high impedance potential source coupled across the other end of the line for energizing the circuit, the output signal of the transducing device being derived across the coaxial line.

Claim 7

A piezoelectric transducer comprising a jacket, a piezoelectric element in said jacket, a P-channel enhancement MOSFET in said jacket having gate, drain and source electrodes, means coupling said piezoelectric element to the gate and drain electrodes of said MOSFET, a two-wire cable connector on said jacket, means in said jacket coupling said connector to the source and drain electrodes of said MOSFET, and a bipolar transistor in said jacket coupling said MOSFET to said cable connector, said bipolar transistor having an emitter, collector and base, said collector being coupled to said MOSFET source electrode and said base being coupled to said MOSFET drain electrode.