A device for measuring an acceleration includes a vibrating accelerometer including: a semiconductor substrate forming a fixed frame of the accelerometer; a test weight of the same material as the substrate and connected to the fixed frame, movable translationally along at least one sensing axis of the vibrating accelerometer; a guide of the same material as the substrate, connected to the fixed frame and test weight, guiding the test weight in the direction of the sensing axis; a layer made of a piezoelectric semiconductor deposited on the substrate, the layer being tensilely prestrained; a resonator in the layer connected to the fixed frame, the resonator subjected to tension or compression in the direction of the sensing axis; and at least one transducer connected to the resonator, able to actuate the resonator, to keep the resonator oscillating and/or to detect an electrical signal generated by the resonator.

Earthquake detector is a solid-state device that detects the motion of a building or structure and initiates an alarm when the motion of a building or structure rises above a certain base level or threshold level of motion that is automatically calibrated or manually entered for the specific building or structure and the specific location of the building or structure. Earthquake detector measures the amplitude of movement and the magnitude of acceleration of the actual building or structure caused by a seismic event, earthquake, or other external force because this is the primary cause of damage to the building or structure and the associated potential for collapse of the building or structure. Earthquake detector has a circuit board; a microprocessor, integrated circuit, or chip; an accelerometer integrated circuit or chip; an alarm module; a connection to a power source; and a calibration control.

The disclosure provides a piezoelectric sensor including a connector and a charge output element. The connector includes a connector housing and a conductive terminal interposed inside the connector housing. The connector housing and the conductive terminal are connected by a first insulating layer. The charge output element includes a base including opposite axially top and bottom ends. A first recess is provided at the top end of the base. A connecting member is disposed inside the first recess along an axial direction of the first recess. A piezoelectric element, a mass block and a fastener are sequentially sleeved on the connecting member. The base includes a second recess formed by recessing an outer peripheral surface of the base toward an interior of the base. The connector is connected to an inner wall of the second recess. A recessed direction of the second recess intersects the axial direction of the base.

The present disclosure relates to a piezoelectric sensor, which comprises a charge output element comprising a first end surface and a second end surface opposite to each other in a length direction, and comprising a base and a connecting member extending from the base in a height direction, wherein a piezoelectric member and a mass are sleeved on the connecting member, and are fixed to the connecting member via a pretensioning member; a connector, disposed above the first end surface of the charge output element with a predetermined distance from the first end surface in the length direction, and comprising a connector housing and a conductive terminal, which is inserted into an interior of the connector housing and connected to the connector housing by a first insulating layer; and a case, containing the charge output element and connected with the connector housing and the base.

An acceleration measuring device includes a piezoelectric system, a seismic mass, and a base plate. The seismic mass exerts onto the piezoelectric system, a force that is proportional to the acceleration. The piezoelectric system responds to the force by generating piezoelectric charges that are electrically transmitted as acceleration signals. The seismic mass includes a first mass element responsible for generating positive piezoelectric charges. The seismic mass includes a second mass element responsible for generating negative piezoelectric charges.

The disclosure provides a piezoelectric sensor, including a piezoelectric crystal cylinder including a plurality of crystal layers which are laminated, each crystal layer including two axially opposite end faces, each end face including an electrode film region and a terminal film region, wherein the electrode film region and the terminal film region on the same end face are separated by a crystal exposure region, the electrode film region on one end face of the two end faces in each crystal layer is electrically connected to the terminal film region on the opposite end face of the two end faces, and the electrode film regions on adjacent end faces of adjacent crystal layers are in contact with each other and form an electrical connection while the terminal film regions on the adjacent end faces of the adjacent crystal layers are in contact with each other and form an electrical connection.

A MEMS sensor comprising preloaded suspension springs and a method for mechanically preloading suspension springs of a MEMS sensor are described. The MEMS sensor comprises a MEMS support structure; a plurality of suspension springs connected to said support structure; and, a proof mass flexibly suspended by said suspension springs; wherein at least one of said suspension springs is mechanically preloaded with a compressive force for reducing the natural frequency of said proof mass.

A device for measuring an acceleration includes a vibrating accelerometer including: a semiconductor substrate forming a fixed frame of the accelerometer; a test weight of the same material as the substrate and connected to the fixed frame, movable translationally along at least one sensing axis of the vibrating accelerometer; a guide of the same material as the substrate, connected to the fixed frame and test weight, guiding the test weight in the direction of the sensing axis; a layer made of a piezoelectric semiconductor deposited on the substrate, the layer being tensilely prestrained; a resonator in the layer connected to the fixed frame, the resonator subjected to tension or compression in the direction of the sensing axis; and at least one transducer connected to the resonator, able to actuate the resonator, to keep the resonator oscillating and/or to detect an electrical signal generated by the resonator.

The present invention consists in a method of welding a nickel strength lug with a bronze connecting pin and a brass contact ring in an accelerometer sensor, the strength lug being interleaved between the connecting pin and the contact ring, the welding being effected electrically with the strength lug pressed simultaneously against the connecting pin and the contact ring. Before welding, the strength lug undergoes deformation of its external surface at least on each of two portions of the surface respectively facing the connecting pin and the contact ring, the surface deformation creating on each of the portions asperities intended to come into local contact with the connecting pin and the contact ring, respectively.

An acceleration measuring device includes a piezoelectric system, a seismic mass, and a base plate. During acceleration of the device, the seismic mass exerts onto the piezoelectric system a force that is proportional to the acceleration of the device. The force causes the piezoelectric system to generate piezoelectric charges that can be electrically processed as acceleration signals. The piezoelectric system includes two system elements, and the seismic mass correspondingly includes two mass elements. The device includes a preloading assembly that mechanically preloads the system elements against the mass elements.