A portable alarm device is positioned in a garment, bag or the like to protect valuable articles located therein, such as wallets. The device includes a casing provided with a power source and a circuit fed by said power source, the circuit including at least one magnetically sensitive element, and at least one signal member serially connected therewith, and a permanent magnetic body attached to the valuable article and cooperating with the at least one magnetically sensitive element to open and close the circuit. In a further refinement, two or more reed switches are connected in series and spaced apart a distance less than the range over which the permanent magnet can control one of the switches so the article can move about within a bag without causing an alarm.

The invention is an improved noise-making device using a piezoelectric transducer where electrical circuit components are mounted directly on the transducer itself rather than being mounted on a separate printed circuit board. Directly mounting the components eliminates the need for a separate circuit board and eliminates a third terminal from a three-terminal device. As a result, the entire device requires less material and labor, and is therefore less expensive. The elimination of the circuit board also can contribute to a reduction in size of the noise-making device.

A visual and audible warning device has a piezoelectric element operable to cause vibrations which are transmitted through a light transmitting member, and a light emitting element which upon actuation causes a visual warning to be transmitted through the light transmitting member. The visual and audible warnings transmitted by the light transmitting member are intended to attract the attention of the operator of a vehicle, such as a boat, above the sound of the engine or other noise. The device has circuit means coupled with the piezoelectric element and the light emitting element for causing a predetermined electrical signal to be applied to the piezoelectric element and causing energization of the light emitting element upon actuation. The device may include a housing having support portions for supporting the light transmitting member and one or more light emitting elements in position while sealing the light transmitting member and electronic components within the housing from the ambient atmosphere, including weather elements which may otherwise result in corrosion and failure of the device.

An apparatus is provided for signalling the falling of bodies in water, comprising a piezo-electric cell for detecting frequency waves less than or equal to 5 Hz and comprising, in a case, a sensor formed of a membrane and a piezo-electric cell connected to a signal amplification and management circuit, in which the effects produced by disturbing frequencies not representative of bodies falling in water, are eliminated, wherein the effects produced by disturbing frequencies are eliminated by dumping or attenuating the frequencies higher the 5 Hz by placing, in the center between membrane 2 and the piezo-electric element 4, an elastomer disk 11 with a Shore hardness between 20 and 25 and forming an elastomer bridge.

The vibratory element of a tone ringer, as used for a telephone set for example, is gripped at its periphery between a ledge on a base housing and a thin deformable extension on a top housing. Interengaging clamping members and wedging members force the top housing down on the base housing when the top housing is rotated relative to the bottom housing. This forces the thin deformable extension into a tight gripping contact with the vibratory element clamping it against the ledge while the thin portion deforms. A ratchet arrangement can be provided to rotationally lock the top housing relative to the base housing. A mounting position for a printed circuit board can be provided on the base housing.