Abstract: A downhole pressure activated device and a method of operating a tool comprises a chamber which has a fluid port for communication between the chamber and downhole fluid located outwith the device. The fluid port preferably comprises a check valve and a fluid flow restrictor connected in parallel, where preferably, the check valve permits fluid flow into the chamber and substantially prevents reverse flow. The chamber is provided with a pressure transmission means by which a pressure in the chamber greater than that in the downhole fluid is capable of being applied to a tool to be operated by the device.

Abstract: A semiconductor device includes an emitter region, a contact region, and a resistive medium. The resistive medium is connected between the contact region and the emitter region. The contact region and the emitter region each include an edge facing each other. At least a portion of the emitter region edge and at least a portion of the contact region edge are non-parallel relative to each other. This configuration enables an emitter ballast resistance to be provided with varied emitter current flow along the injecting edge of the emitter. Furthermore, by including an additional contact and an additional resistive medium between the contacts, the ballast resistance of the semiconductor device can be increased without decreasing the figure of merit of the device.

Abstract: A system and method is disclosed for feedback velocity control of a D.C. motor. The system includes a motor (30) which is represented by its circuit equivalent--a series combination of an inductance (32), a resistor (34) and a back EMF source (36). The drive to the motor (30), supplied by a controller, is periodically inhibited by timing logic (22) and AND gate (20). Once the inductive transient decays via clamping diode (38) such that the motor current is zero, switch (40) is closed and the internally generated motor voltage is sampled by a capacitor (42). A/D converter (44) transforms the sampled value to a digital value and sends it to the controller. The controller compares it to a predetermined desired value then makes the necessary adjustments to the drive signal.

Abstract: Apparatus and method are provided for determining and indicating if certain types of circuit failures have occurred in a D.C. motor circuit such as a locked rotor condition, a short-circuit or an open circuit. The method includes the steps of, and the apparatus involves applying a voltage to two leads of the D.C. motor sufficient to cause motor rotation, determining if flyback exists, determining if back EMF exists, and, finally, if a back EMF does not exist and flyback does exist then indicating a locked rotor condition. However, if a back EMF does not exist and flyback does not exist then an indication is provided that either an open-circuit or short-circuit condition exists. The same apparatus and method can be used with a voltage not sufficient to cause motor rotation, although given this limitation only flyback can be detected, so that only an open-circuit or short-circuit condition can be indicated.

Abstract: Apparatus and method are provided for determining indicating if certain types of circuit failures have occurred in a D.C. motor circuit such as a locked rotor condition, a short-circuit or an open circuit. The method includes the steps of, and the apparatus involves, applying a voltage to two leads of the D.C. motor sufficient to cause motor rotation, determining if flyback exists, determining if back EMF exists, and, finally, if a back EMF does not exist and flyback does exist then indicating a locked rotor condition. However, if a back EMF does not exist and flyback does not exist then an indication is provided that either an open-circuit or short-circuit condition exists. The same apparatus and method can be used with a voltage not sufficient to cause motor rotation, although given this limitation only flyback can be detected, so that only an open-circuit or short-circuit condition can be indicated.

Abstract: A very deep P.sup.+ diffusion step is performed prior to the definition of a self-aligning emitter/P.sup.+ region. Furthermore, the initial P.sup.+ region is formed with dimensions sufficiently narrow to allow the subsequent emitter/P.sup.+ formation step to overlap the deeper P.sup.+ step by enough distance for the P.sup.+ step to completely cover the deep P.sup.+ region with its significant lateral diffusion. In this manner, a low sheet resistance in combination with proper alignment of the P.sup.+ heavy region with the emitter region is obtained.

Abstract: A biasing device for actively biasing the base of an RF device operating in quasi-linear modes. The biasing device provides a source of low-impedance current and high current capability. The biasing device includes three transistors, each having a base, collector and emitter and one low turn-on diode. The first and second transistors are connected such that changes in the base-emitter voltage of the biased RF device can be detected. The third transistor is configured in a Darlington configuration with the first transistor in order to provide (1) increased sensitivity to voltage changes detected by the second transistor and (2) additional collector voltage for the second transistor to prevent it from operating in saturation. The low turn-on diode is a compensating diode which thermally tracks and compensates for operating changes in the second transistor due to temperature.

Abstract: A high frequency, high power transistor is vertically isolated by providing a thermally conductive, electrically insulating substrate, upon which the transistor components (including collector, base, and emitter) are grown, positioned directly on the heat sink and a planar top surface formed on the transistor by the base metal contact, the emitter metal contact, and the collector metal contact. Vertical isolation improves the thermal management capabilities of the transistor. Moreover, such a vertically isolated transistor is well-adapted for lateral isolation, which solves the capacitance problems inherent in conventional devices.

Abstract: Apparatus for displaying operating conditions of a device in which voltages that are produced when respective operating conditions exist are formed into a series of pulses with a bracket pulse on at least one end of the series and a display of indications of the presence of pulses at locations corresponding to their positions in the series.

Abstract: The ballast resistance of a semiconductor device is increased without decreasing the figure of merit of the device. The semiconductor device includes an emitter feeder, a first contact coupled to the emitter feeder, a second contact, a resistive medium connected between the first contact and the second contact, an emitter, and a further resistive medium connected between the second contact and the emitter. The ballast resistance of the semiconductor device is increased without decreasing the figure of merit of the device by increasing the distance between the first contact and the second contact.

Abstract: A biasing device which is in thermal contact with an RF device for actively biasing the RF device operating in quasi-linear modes. The biasing device provides a low impedance current source with high current capability to the base of the RF device. The biasing device includes three specially-processed transistors. The second and third transistors are connected such that their base-emitter and base-collector junctions are in parallel effectively forming two exceptionally low turn on series diodes. The result of reducing the resistances of the second and third transistors, by configuration and processing, is that they turn on slightly before the RF device is biased to its quiescent point.

Abstract: Using a silicon etched technique to remove an implanted base and emitter surrounding emitter-base islands, a "mesa" emitter structure can be formed. Using the structure, a self aligned P+ can be formed around emitter-base islands.

Abstract: A biasing device for actively biasing the base of an RF device operating in quasi-linear modes. The biasing device provides a source of low-impedance current and high current capability. The biasing device includes three transistors, each having a base, collector and emitter and one low turn-on diode. The first and second transistors are connected such that changes in the base-emitter voltage of the biased RF device can be detected. The third transistor is configured in a Darlington configuration with the first transistor in order to provide (1) increased sensitivity to voltage changes detected by the second transistor and (2) additional collector voltage for the second transistor to prevent it from operating in saturation. The low turn-on diode is a compensating diode which thermally tracks and compensates for operating changes in the second transistor due to temperature.

Abstract: A semiconductor device is manufactured with precisely formed base and emitter regions. This is accomplished by arranging a plurality of insulator layer portions to form a plurality of windows. A dopant is then applied to the semiconductor device between the windows in order to accurately position emitter regions relative to base regions. In this manner a base of controlled dimensions can be formed. Thus the parasitic resistance of the base can be reduced and the figure of merit (emitter periphery/base area) can be increased.

Abstract: A wafer substrate test structure and method provides a novel means for quantitatively determining electrical isolation between active devices and passive elements in a monolithic integrated circuit. The structure and method of this invention are useful for both optimal design and manufacture of integrated circuit devices.

Abstract: Linear high gain (greater than 20 dB) and high power (greater than +20 dbm) devices for RF power amplifiers are achieved using either fully monolithic or hybridized versions of silicon MMIC two-stage cascaded amplifiers. The device features three feedback loops in conjunction with a DC biasing network. Resistor-capacitor feedback circuits utilize only two capacitive elements which are provided as a single three-terminal element having a common lower plate.

Abstract: A module for use with a radial combiner comprised of a compartment on one side of a base that contains a plurality of amplifiers located on a printed circuit board having conductive patterns respectively coupling the amplifiers between points along a serial splitter and points along a serial combiner in which operating potential for the amplifiers is derived from storage capacitors connected between two conductors on a separate board via conductive spring fingers having one end attached to one of said conductors and the other end bearing against a conductive pad on the printed circuit board that is coupled to an electrode of an amplifier and in which a plenum is mounted along one edge of the module for conducting cooling air to a duct on the other side of the base.

Abstract: Printer having a sheet feed and drum transport assembly, an exit assembly and at least one dryer. Various print parameters or conditions are monitored relating to the drying of the ink on print media. These print parameters include print data density, ink characteristics and ambient humidity. The monitored print parameters are used to control the drying. In addition the monitored print parameters are used to control the detaching of the print media from a rotary transport. In this manner, the printer approaches an optimization of the drying and detaching function with respect to time and energy.

Abstract: A volume ventilator having a plurality of integrated modes of operation for providing a patient with a flow of breathing gas under pressure. A plurality of adjustable setting devices each producing an individual threshold signal related to a parameter of the gas flow. Mode switching means provides for the selection of at least one mode signal. Each threshold signal is compared with a common variable signal for producing a plurality of control signals. At least one of the control signals is selected in accordance with the selected mode signal and that control signal is applied to a valve system for controlling flow of gas to the patient. In this manner, the setting devices may be continuously adjusted to change one or more of the threshold signals without varying any of the other threshold signals. There is further provided a comprehensive system of alarms.