Abstract: Apparatus for measuring a characteristic of motion and methods for its manufacture are disclosed in which a sensor structure includes a support structure, and a mass suspended from such support structure by a spring connecting arrangement and electrical devices for measuring displacement of the mass which results from a force applied to the support structure. An apparatus is provided where the mechanical spring constant of the connecting arrangement of the sensor structure is provided to be a high value representative of a strong, stiff spring which resists breaking due to high forces applied to it, and where an electric spring constant is provided to yield a small effective sensor spring constant K.sub.eff =K.sub.m -K.sub.e. Methods are also provided to manufacturing the apparatus by specifying the mechanical spring constant and providing an electric spring constant which will yield a desired effective spring constant which produces a desired characteristic of the sensor structure.

Abstract: A sensor structure (10) has a central mass (16) mounted within a support structure comprising an outer support frame (18), and upper and lower plates or covers (12, 14). Eight L-shaped ribbon springs (32, 34) fit about the corners (28) of the mass (16) to mount mass (16) for movement from a reference position with respect to the support structure. One leg (38) of each spring (32, 34) is connected to an associated side (26A) of the mass (16) centrally of the length of the associated side (26A). The other leg (40) is connected to the outer support frame (18). The sensor structure is designed for use as a sensing mechanism in an electrostatic accelerometer arrangement.

Abstract: A method for fabricating a connecting spring member (24) of an arbitrary shape extending between a central mass (21) and an outer support frame (23) of a sensor as shown in FIG. 7 is disclosed. Each of a pair of generally identical silicon wafers (10, 12) has an inner etch stop layer (16) applied to one face with an outer epitaxial layer (18) formed over such etch stop layer (16). A photosensitive oxide layer (30) is applied to the other face of each of the wafers (10, 12). Next, a pattern of the central mass (21) and outer support frame (23) as shown in FIG. 2 is photographically imposed on the photosensitive oxide layers (18) of each wafer (10, 12). After wet chemical etching of the wafers (10, 12) removes silicon material to the etch stop layer, and the etch stop layer is itself removed in the space between the mass and the frame, the two wafers (10, 12) are bonded to each other as shown in FIG. 5 .

Abstract: A solid state keyboard comprised of a base module, a plurality of key members each having a plunger member comprised of a uniform mixture of a magnetic material such as barium ferrite and a binder such as nylon, and a respective plurality of improved Hall Effect Generators, provides a significant improvement in performance and cost effectiveness. Actuation of a key member moves its plunger member, which has a preselected magnetic field, relative to an improved Hall Effect Generator, in which offset voltage has been substantially eliminated. This movement exposes the generator to a change in the direction of the magnetic field, thus causing a corresponding change in the output voltage of the generator from a first predetermined voltage to a second predetermined voltage. A unique tripolar magnetic arrangement on the plunger member provides positive switching and better control of switching points.

Abstract: A semiconductor body has formed on it at least two hall effect plates each having a pair of oppositely positioned current contacts and a pair of oppositely positioned hall voltage contacts, the hall effect plates being positioned with respect to each other such that a line of one bisecting the current terminals is generally orthogonal to a line of the other bisecting the current terminals. Means are provided for applying a voltage across the current terminals of both of the hall plates and means are provided for selectively applying a magnetic field that intersects substantially perpendicularly the plane of the hall plates. The positive hall voltage contacts are connected together and the negative hall voltage contacts are connected together, with output circuitry connected to this interconnecting circuitry for receiving and transmitting an electrical signal indicative of the presence of the intersecting magnetic field.