Abstract: A cost-effective communication filter is prepared by etching the surfaces of a shaped and fired ceramic core, applying an electroless nickel solution to create a nickel layer of limited thickness, electroplating the nickel plated core with a silver layer, patterning the nickel and silver plated core by removing metallization from selected surface areas and then heating the patterned filter block to bond the metal layers. The resulting filters comprise a rigid dielectric core defining a plurality of through-hole passages extending between opposing sides of the core. Present on the core is a pattern of metallized and unmetallized regions wherein the metallized regions of the pattern include an inner layer of nickel and an outer silver-containing layer.

Abstract: A dual-range crystal oscillator module comprises lower and upper wiring board panels each having a component side, a surface mount side, a central portion and an outer edge portion including a plurality of input-output contacts. A lower set of crystal oscillator components is mounted to the lower wiring board panel such that the lower set and the lower wiring board panel define a first crystal oscillator circuit. An upper set of crystal oscillator components is mounted to upper wiring board panel such that the upper set of crystal oscillator components and the upper wiring board panel together define a second crystal oscillator circuit. A side-wall frame is attached between the upper and the lower wiring boards providing connections between the input-output contacts of the upper wiring board panel and the input-output contacts of the lower wiring panel.

Abstract: A frequency controlled oscillator (100) is manufactured using an array (200) of mechanically interconnected oscillator bases (110) having component cavities (130) and wiring patterns therein. A frequency control component (120) serves as a cover for a cavity within the array, and in addition is electrically connected to oscillator components (140, 150) mounted within the cavity to regulate the frequency of electrical oscillation. Both the oscillator bases and finished oscillators may be tested while still in the array, prior to being separated from each other. In a most preferred embodiment, the array of oscillator bases are manufactured from a polymeric sheet material laminated with electrically conductive traces. The polymeric sheet material is selectively punched or formed prior to lamination so that intermediate and upper layers (112, 113) have predetermined sections removed.

Abstract: A frequency-adjustable oscillator suitable for digital signal clock synchronization comprises a crystal oscillator circuit for generating a driving signal and having a voltage-variable control input for adjusting a frequency of the driving signal, a phase detector circuit for generating a phase offset signal, a filter which operates on the phase offset signal to produce a VCO control signal, a voltage controlled oscillator circuit operably linked to the filter and responsive to the VCO control signal for generating an analog controlled-frequency signal, a frequency divider circuit for generating a reduced frequency feedback signal in response to the controlled-frequency signal, and a sinewave-to-logic level translator circuit for generating a digital output signal having substantially the same frequency as the controlled-frequency signal. The crystal oscillator circuit includes a discrete varactor responsive to the control input and a fundamental mode AT-cut quartz resonator.

Abstract: A method and apparatus are provided for generating a control signal for compensating a temperature controlled crystal oscillator system for changes in an ambient temperature. The method includes the steps of providing a set of second-order coefficients relating ambient temperature to frequency drift over at least a portion of an operating temperature range of the temperature controlled crystal oscillator system and calculating a control signal for compensating the temperature controlled crystal oscillator system for the frequency drift due to the ambient temperature based upon the set of second-order coefficients.

Abstract: A frequency-adjustable oscillator suitable for digital signal clock synchronization comprises a SAW oscillator circuit for generating an analog controlled-frequency signal and a sinewave-to-logic level translator circuit in a double-sided package. The SAW oscillator circuit includes a tunable SAW resonator, a gain stage for energizing the SAW resonator, a voltage-variable control input for adjusting a frequency of the controlled-frequency signal, and a voltage-variable capacitive element operably linked to the SAW resonator and responsive to the control input. The sinewave-to-logic level translator circuit is operably linked to the SAW oscillator circuit and configured to generate a digital logic output signal having substantially the same frequency as the controlled-frequency output signal.

Abstract: A device for generating conditioned electrical signals in response to forces applied to the device. The device includes a shaft attached to a substrate. Several strain sensitive resistors are mounted on the substrate around the shaft for generating an electrical signal representative of a magnitude and direction of force applied to the shaft by a user. Several apertures are in the substrate, each aperture is located between a pair of strain sensitive resistors. The apertures concentrate the stress on the resistors. A signal conditioning device is mounted to the substrate and is electrically connected to the resistors for conditioning the electrical signal. The signal conditioning device receives the electrical signal in an analog form and provides a conditioned signal as an output in a digital form. The device is mounted to a keyboard base. An alternative embodiment is shown using a cavity instead of apertures in the substrate.

Abstract: A control device, like a pointing stick, for controlling the positioning, movement and operation of a responsive electrical device, like a cursor on a computer display screen. There is a compact gimbal mounted joystick 10 that has a stick assembly 14; a gimbal assembly 12 having the stick assembly mounted thereon; a sensor 42 and 44, mounted to the gimbal assembly, for generating an output signal indicative of a position of the stick assembly; and a switch 50, positioned below the stick assembly, to be activated when the stick assembly is sufficiently displaced to close the switch. Additionally there is a biasing means 56, positioned about the switch and extending to the gimbal assembly, the biasing means forcing the gimbal assembly into a centering position when not in use.

Abstract: A weighing device designed to accurately measure an object's weight that is easier and more cost effective to produce. In particular, the device consists of a strain gage load cell having a pair of substrates mounted in parallel. The first and second substrates each contain a pair of resistors which are embedded in the surface of the substrate pair, forming a Wheatstone Bridge configuration. The substrates may be formed of ceramic.

Abstract: A two-phase electro-mechanical stepper motor has a first and second rotor fixed on a shaft. Permanent magnets are mounted on each of the rotors. The magnets each have several north and south pole magnet regions that are oriented such that the magnet's north and south pole magnet regions are misaligned with respect to the other magnet's north and south pole magnet regions. A first and second stator are mounted around the shaft and positioned adjacent to the permanent magnets. The stators have coils that are wrapped around poles to allow the formation of electromagnets by passing electrical current through the wire coils. A gear train is positioned between the first and second rotors to obtain a higher torque output.

Abstract: A low profile integrated oscillator operable to provide an oscillator signal includes a thermally conductive substrate having a cavity and a ledge. A crystal or other resonator is located in the cavity and mounted to the ledge. The resonator stabilizes the oscillator signal. An electrical circuit is mounted to the substrate and electrically connects to the resonator to condition the oscillator signal. A cover seals the resonator in the cavity. A via electrically connects the resonator to the electrical circuit. A heater is mounted to the substrate, outside the cavity, for elevating the temperature inside the cavity and a temperature sensor is mounted to the substrate to monitor the oscillator temperature. The substrate is surrounded by an insulation and mounted within a housing. The housing has a connector for connecting to an external electrical circuit.