An electronic sound generating apparatus includes a housing having a closed end and a sidewall defining a cavity. The sidewall also includes a series of radially arrayed sound radiating ports. A circuit board with power source, a sound generating element electronically connected to the circuit board and a sound reflector are all received in the cavity. The sound reflector includes a substantially conical face axially aligned within the cavity and directed toward the sound generating element. This face serves to radially reflect the sound from the sound generating element through the series of sound radiating ports. A touch plate and normally open switch are also housed in the cavity with all the components maintained in position by means of a retaining ring. The switch may include a pair of spaced, relatively stationary contacts mounted to the sound reflector as well as a collapsible or compressible trigger member with a relatively displaceable contact. When the touch plate is depressed, the displaceable contact engages and bridges across the stationary contacts to close the switch and actuate the sound generating apparatus.
A buzzer, which includes a casing, a diaphragm supported on an upright annular supporting flange inside the casing, and a circuit board mounted within the casing and electrically connected to the diaphragm, wherein the casing has locating ribs symmetrically disposed on the inside for the positioning of the circuit board in the casing; the circuit board has three metal contact spring elements raised from the bottom side wall thereof and respectively maintained in contact with respective conductive zones at the diaphragm, and a plurality of peripheral notches respectively matched with the locating ribs in the casing.
A sound generator, in particular for parking assistance systems for vehicles, has a housing (2) comprising a base part (4) and a top part (6), wherein the base part (4) defines a receiving space (8, 10), which can be covered by the top part (6), for receiving a diaphragm (38). The base part (4) is formed as one part together with the top part (6) via a connecting section (28), wherein the base part (4) and the top part (6) can be moved relative to each other and can be joined by a joining device (26).
A personal security alarm in the form of a wearable case containing an sonic alarm transducer, a capacitor power supply, and a manually operable trigger for completing an electrical circuit between the power supply and the alarm transducer to operate the transducer by discharging the power supply. An oscillator is electrically connected between the power supply and the alarm transducer when the trigger operates, to output a variable frequency signal. An amplifier electrically connected between the oscillator and the alarm transducer amplifies the tone signal and drives the alarm transducer with the amplified signal. The oscillator can be programmed with a predefined variable frequency signal. A charger can be coupled through the case to charge the capacitor power supply without removing the power supply from the case. If the alarm is triggered, a catch mechanism must be released to deactivate the sonic alarm prior to completion of a preset interval, thus thwarting potential deactivation of the alarm, should an attacker seize control of it.
A sound generating device is mounted in a recess formed in a case, and a battery is mounted on the case. A pair of terminals are provided on the underside of the case. A pair of leads connect a pair of electrodes of the battery with the terminals.
An individual acoustic wave switch includes a body with a top section having an acoustic wave cavity formed therein and a base section extending downwardly from the top section. An acoustic wave transducer is mounted adjacent to a surface of the acoustic wave cavity opposite the touch surface thereof so as to generate an acoustic wave in the acoustic wave cavity and to pick up a signal representing the acoustic wave energy in the cavity. The acoustic wave switch is readily mounted in an aperture of a substrate through which the base of the switch extends.
