Abstract: A sensor system is formed from a micro machined resonant structure with multiple resonant elements, a tracking resonator control electronics, and signal processing algorithms. The moving elements of the resonator are coated with chemically active materials that change mass when exposed to the target chemical resulting in a change in frequency or period of oscillation. The changes in frequency or period are processed by multi-sensor chemical detection algorithms to identify chemical types and concentrations. In essence, the resonator and drive electronics form a closed loop oscillator operating at the resonator's natural frequency. The resonators are formed from silicon using photolithographic processes. The resonator design includes in-plane resonant motion combined with dynamic balance to operate with a high Q even in the presence of atmospheric pressure.

Abstract: A sensor system is formed from a micro machined resonant structure with multiple resonant elements, a tracking resonator control electronics, and signal processing algorithms. The moving elements of the resonator are coated with chemically active materials that change mass when exposed to the target chemical resulting in a change in frequency or period of oscillation. The changes in frequency or period are processed by multi-sensor chemical detection algorithms to identify chemical types and concentrations. In essence, the resonator and drive electronics form a closed loop oscillator operating at the resonator's natural frequency. The resonators are formed from silicon using photolithographic processes. The resonator design includes in-plane resonant motion combined with dynamic balance to operate with a high Q even in the presence of atmospheric pressure.

Abstract: Dynamic operation of a brushless N-phase DC motor results in a high torque constant (Kt) line-to-line phase configuration during spindle motor power-up, and in a lower effective Kt configuration once normal run speed operation is attained. When the spindle motor is rotating below a predetermined run speed, drive transistors coupled to the motor phases cause at least two phases to be series-coupled between the source of operating voltage and ground. This ensures a large initial torque because the Kt contribution of each series-coupled phase is combined vectorially. Once run speed is achieved, effective Kt is lowered by causing the drive transistors to energize but a single phase, reconfiguring the spindle motor for line-to-neutral operation. So doing reduces the effective back electromagnetic force, permitting sufficient run current from a given magnitude operating voltage source.

Abstract: Apparatus is disclosed for controlling the movement of a movable element to bring said movable element to rest at a desired stopping position. The apparatus comprises a multi-phase drive motor having a drive shaft coupled to the movable element for driving same, a plurality of electrically conductive coils mounted in position-displaced relationship about the shaft, and means coupled to the drive shaft and responsive to the selective energization of the coils by respective motor drive signals for causing the corresponding rotation of the drive shaft and movement of the movable element. A sensor is coupled to the drive shaft and is responsive to the rotation thereof for generating an electrical signal containing information indicative of the direction, speed and distance of movement of said movable element. Further, means are included for detecting from the distance information indicated by the electrical signal whether the movable element is within a predetermined distance of the desired stopping position.

Abstract: Apparatus is disclosed which is responsive to the movement of a movable element for generating a plurality of electrically phase-displaced signals containing information indicative of the direction, speed and distance of movement of said movable element. The apparatus comprises a plurality of position-displaced electrically conductive coils and a permanent magnet mounted adjacent each of said coils for producing a path of normally substantially constant magnetic flux adjacent each of said coils. A flux varying device is coupled to the movable element and is responsive to the movement of the movable element for varying the level of the magnetic flux adjacent each of the coils in dependence upon the direction, speed and distance of movement of the movable element, whereby the resultant electromotive force induced in each of the coils defines the plurality of electrically phase-displaced signals.

Abstract: Apparatus is disclosed for controlling the movement of a movable element to bring the movable element to rest at a desired stopping position.

Abstract: Apparatus is disclosed which is responsive to the movement of a movable element for generating a plurality of electrically phase-displaced signals containing information indicative of the direction, speed and distance of movement of the movable element. The apparatus comprises a plurality of position-displaced electrically conductive coils; a permanent magnet mounted adjacent each of the coils for producing a path of normally substantially constant magnetic flux adjacent each of the coils; and a flux varying device coupled to the movable element and responsive to the movement of the movable element for varying the level of the magnetic flux adjacent each of the coils in dependence upon the direction, speed and distance of movement of the movable element, whereby the resultant electromotive force induced in each of the coils defines the plurality of electrically phase-displaced signals.