Abstract: A dual function transducer housing (100), includes a narrow profile housing having top and bottom cavities (105, 103) and a ringer side port (106). The top and bottom cavities (105, 103) are adapted to receive a ringer diaphragm and a speaker diaphragm, respectively. The top cavity (105) is in communication with the ringer side port (106). A ringer output signal is providable through the ringer side port (106) and a speaker output is providable from the housing (100).

Abstract: A piezoelectric transducer (100) may be achieved by mounting a piezoelectric bender (101) within a housing (102). Maximum resonation may be obtained by mounting the piezoelectric bender (101) on a single post (103). The housing (102) is constructed to have essentially the same geometry as the piezoelectric bender (101) and is separated by a predetermined distance (104). This predetermined distance (104) provides an acoustic impedance such that sound may resonate from the transducer.

Abstract: In applications where mechanical vibrations should not cause a microphone to produce an output signal, opposing and series connected PZT elements (A and B) are used to cancel mechanical shock or vibration that might cause an output voltage or signal. Acoustic waves cause the PZT elements to deflect in opposite directions which when the sensors (A and B) are electrically in series produce a measurable output.

Abstract: A preferred embodiment of a thermal protection circuit for a piezoelectric speaker includes a PTC resistor connected in series with the speaker and a second PTC nonlinear resistive element, such as a light bulb, connected in parallel with the resistor. This protects the speaker from failure due to overheating caused by excessive drive signals without causing audio distortion during infrequent excessive drive signals of a short duration.

Abstract: A helmholtz resonator is driven by a piezoelectric element and is suited for mounting to a printed circuit board. The resonator includes a resonant chamber defined by bottom, top, and side walls, and at least two ports that provide access to the chamber. The ports are contiguous to the bottom and side walls so that any liquid entering the chamber during the printed circuit board cleaning process can exit via the ports. This arrangement overcomes the contamination problem existing in prior art resonators having a single port.

Abstract: A communications headset in which a unidirectional microphone at the end of a support boom is adjustably secured in a position selected by the wearer. The support boom is clamped under adjustable compression in a ball-and-socket arrangement which, at reduced compression, allows the boom to be moved longitudinally, pivoted about its axis, or pivoted about the center of the ball. The wearer turns a knob to compress the ball-and-socket joint to secure the boom in the position desired. A tube transmitting sound from the receiver to an ear plug is adjustably attached to the headset by means of a second ball-and-socket joint. A pivoting clamp attached to a pivoting temple member permits the microphone support assembly to be switched from one side of the head to the other as desired.

Abstract: A miniature acoustical transducer. The transducer includes a diaphragm, spring member and electromagnetic coils secured within a substantially cylindrical housing. The coils are arranged on opposite sides of the spring member. The spring member carries a permanent magnetic member and is connected to the diaphragm. Movement of the magnetic member relative to the electromagnetic coils varies the reluctance of the magnetic circuit defined by the coil and an associated core member.