Abstract:
A connector is made by cutting a continuous strip (60) of conductive material to provide individual fingers that extend in a direction perpendicular to the length of the strip. The fingers (71, 72, 73, 74) are individually bent to offset their distal (66) ends from their connective ends. The process defines bend lines (78, 79) on each of the fingers and then bends the fingers to offset their distal (66) ends from their respective connective ends in directions perpendicular to the plane of the conductive strip (60) and along its length. After appropriately bending each of the fingers, a nonconductive material is molded around the group of fingers. Following the molding operation, the connective ends of the fingers are severed from the uncut portion of the strip to singularize an electrical connector from the continuous strip of connectors.
Abstract:
A GHz-range frequency-modulated laser based on manufacturable vertical cavity surface emitting lasers (VCSELs) and arrays. The present invention exploits a saturable absorber contained within the VCSELs distributed Bragg reflector which may itself be adjusted during fabrication or in operation. Under controllable operating conditions, the saturable absorber, strategically sized and placed, will force the VCSEL to self-pulsate (in the GHz-regime) at rates related to the local intensity, absorption, lifetime, and carrier density of the saturable absorber. These conditions can be controlled in real time in one of three ways; first, by adjusting the injection current into the VCSEL itself; second, for a fixed VCSEL bias and the use of a third terminal, by modifying the carrier density within the saturable absorber via additional current injection; or third, the saturable absorber can be reverse-biased by simultaneously altering its absorption and carrier lifetime and thus carrier density. Additionally, the frequency response can be controlled in the fabrication process by affecting the location of the saturable absorber, the mirror design and cavity Q, and the laser size (and hence threshold current). One can easily multiplex numerous GHz channels into a 100 plus GHz transmitter in a cost-effective manner. Application of the saturable absorber for self-pulsation provides for a decoherence of the VCSEL light output to eliminate modal noise in data communication systems, or for use as a local oscillator in an RF or other system. A plurality of VCSELs may be formed into an array having various frequencies, intensities, phases or other properties. The VCSELs may form a phased array, for instance.
Abstract:
An adaptive recovery method for a setback thermostat using the intersection of the space temperature with a sloped recovery temperature line which approximates the change in temperature as a function of time during recovery of the temperature controlled space from a setback temperature, to determine the time at which recovery to the occupancy temperature should begin. The thermostat starts recovery when the current space temperature crosses the recovery temperature line. A useful feature of the apparatus and method which implements the invention, computes and constantly updates the slope of the temperature recovery line. The update of the temperature recovery line slope is based on miss time, i.e., the time between actually achieving the desired next set point temperature and the next set point time associated with the next set point temperature, the space temperature, the outdoor air temperature, the temperature recovery ramp rate during the previous recovery period, and the current and past thermal time constants. If the heating or cooling load on the space changes, the current space temperature will cross the recovery temperature line at a different time, causing recovery to start at a time more compatible with the current heating or cooling load in order to complete recovery at or near the desired time. Variables may be added to the system.
Abstract:
A device for providing a bias modulation at a proper frequency to the counterpropagating light waves in the sensing coil of an interferometric fiber optic gyroscope. The photodetector (13) detects the light which has exited the sensing loop, and converts it to an electrical signal that is demodulated by two phase sensitive detectors. One phase sensitive detector (36) demodulates the signal that is in phase with the bias modulation signal and the other phase sensitive detector (35) demodulates the quadrature signal with respect to the modulation signal, and controls the frequency of the bias phase modulator driver (60) so as to reduce the quadrature to a minimum and to keep the modulator frequency at the proper frequency of the sensing coil (10). Increased intensity modulation can be attained with a DC voltage applied to an electrode of the modulator to produce the quadrature signal. In the digital implementation, higher harmonics are introduced to the modulator to increase the quadrature signal for improved sensitivity of the proper frequency of the sensing coil.
Abstract:
The invention is directed to methods, together with apparatus for implementing such methods, for providing display screens and operator interfaces for process control and measurements, comprising the steps of (a) graphically defining and generating Display Libraries that can be used by a stand alone process control and/or process measurement instrument containing an interpretation engine (a software task designed to interpret Display Definitions) to actually render displays and control their appearance and behavior during real time process operations; and (b) interpreting the contents of the aforesaid Display Definitions (using said interpretation engine) during the normal operation of a stand alone instrument, thereby rendering displays having the defined appearances and behaviors. By using the invention, display screens and operator interface controls can be created, provided to and executed on a wide range of user process control and measurement instruments which run on platforms that are otherwise incapable of supporting a display editor.
Abstract:
A silicon accelerometer includes several silicon layers. The silicon layers form two silicon beams supported by flexure members. An accelaration responsive silicon mass is arranged to bend the flexure members in response to accelerations. The silicon beams are vibrated in vacuum chambers and gas damping is provided for the acceleration responsive mass and the flexure members. Sensing electronics detect vibration of the two silicon beams.
Abstract:
A photoconductor (10) has an active layer (20) of gallium nitride having approximately 10 to 5 x 10 net donor sites per cubic centimeter and is sensitive to UV radiation. This photoconductor has at least one of a sheet resistance in the approximate range of 10 to 5 x 10 ohms/unit area and a relatively low level of photoluminescence in the range from about 430-450 nm when excited with light of energy higher than the bandgap energy of 3.4 eV. These criteria tend to define similar semiconductor materials which can form the active layer of an ultraviolet (UV) photodetector having the improved characteristics of a relatively low dark resistance, high sensitivity over at least a range of UV radiation intensity, and decreasing gain with increasing UV radiation.
Abstract:
A magnetic sensor is provided with a carrier that has a cavity (104) shaped to receive a magnet (24) in sliding association therein. Ribs (110, 112) are provided to guide the movement of the magnet into the cavity and a deformable rib (120) is used to hold the magnet at a precise position determined by an active calibration process. A magnetically sensitive component (10) is rigidly attached to a substrate (140) and the substrate is rigidly attached to the carrier (100) in which the cavity is formed. Electrically conductive leads (130, 132, 134) are molded into the carrier and extend through the carrier to positions where they can be electrically connected to circuit runs on the substrate. A flexible wall (122) can also be formed in the carrier to deflect in response to the insertion of a magnet into the cavity. This provides additional holding capability that retains the magnet in position when an external force is removed.
Abstract:
At least one microbeam situated on a substrate, having a resonant frequency dependent on the strain on the microbeam which may be affected by the bending of the substrate. The beam or beams have sense and drive electrodes proximate to the beam or beams and form capacitors with a beam being the other electrode. The capacitance varies as the beam moves in vibration. The sense electrode is connected to an input of a transistor, such as the gate or base, and the drive electrode is connected to an output of the transistor. The transistor has a load impedance with a capacitive component to aid in the sustaining of vibration of the beam at a resonant frequency. A high ohm resistor is connected between the gate and the drain of the transistor to appropriately bias the gate. The bending of the substrate may be caused by a magnitude of a physical stimulus being measured. However, the bending of the substrate is not utilized nor desired in the filter and temperature sensing configurations of the invention. The frequency of resonance is an indication of the magnitude of the physical parameter. Variants of the sensor may be implemented with different placements of the sense and drive electrodes, and additional electronics as needed to implement the various configurations and microbeam geometry. Additional sense and/or drive electrodes and beams also may be incorporated in the transistor resonant microbeam sensor.