Abstract: A circuit for providing DC bootstrapping to an AC amplifier integrates a sample of the output of the amplifier and feeds the result of that integration to the input of the amplifier, thereby driving the input of the amplifier to a zero potential level. The integration can be accomplished by an operator amplifier and a capacitor in a feedback circuit.

Abstract: A gravity operated switching circuit, having particular application in end of train equipment, allows the microprocessor circuit board in the equipment to be turned off. The circuit turns the power off when the equipment is laid on its side after a predetermined time constant, and when the equipment is again mounted in an upright position, the power is turned on after a different predetermined time constant. A modification of the basic circuit requires a reset button to be manually pressed to restore power after the equipment is again mounted in an upright position.

Abstract: A portable transmit/receive induction balance type metal detector having an automatic ground exclusion balance (GEB) feature to facilitate the screening out of the effects of mineralized ground. The circuitry provides a static GEB in a single try and then, if selected by the user, continual automatic GEB on a dynamic basis as the system is used. The circuit includes a pair of quadrature phase detectors, one of whose outputs is approximately in phase with the ground component of the loop return signal. That output is modified, during an air balance of the detector, to remove the residual offsets in the circuit. This modified output in turn is summed with the other phase detector output to produce a phase detection signal that can be adjusted by automatic means to be precisely in quadrature with the ground component of the loop return signal. A controller is provided, with selectable user inputs, to initiate the static and dynamic GEB operations.

Abstract: A pattern recognizing content addressable memory system and method therefor, according to the present invention, "translates" patterns into a point in N-dimensional space. In both the analog and digital embodiments of the invention, data representing "items" or "discrete pieces" of reference patterns are stored throughout a highly-interconnected network of processing units. Data representing items of a pattern to be analyzed are input into the system and compared to each of the stored patterns. The distance between the point in N-space representing an unknown pattern and the point representing a reference pattern is inversely proportional to the degree of similarity between the unknown pattern and the reference pattern.

Abstract: A personal electronic communication apparatus for carrying by an individual including, a housing having an indicator panel for displaying received information characters or the status of the apparatus located on the front face of the housing. The housing has a normal right-side-up orientation in which all of the information characters being displayed may be read in a normal fashion. A support device includes normally parallel front and back plates, with a hinge mechanism pivotally joining the upper portions of the plates and is adapted to be vertically inserted around a belt or to clip on to a pocket flap, with the hinge mechanism projecting upward. The front plate has means for fastening it to the back face of the housing in such an orientation that the indicator panel is normally up-side-down with respect to the individual carrying the apparatus, that is, the indicator panel faces away from the person carrying the apparatus.

Abstract: A counterelectrode and a method for providing the counterelectrode wherein an inherently high effective capacitance surface is formed on tantalum. The oxide forming ability of the tantalum surface is destroyed by removing existing oxide from the surface, depositing on the surface a non-continuous layer of a platinum family metal, and alloying the deposited metal with the tantalum thereby forming alloy layer. A second layer of metal, also selected from the platinum family, may then be deposited over the alloy layer. Alternately the platinum family metal may be sputtered onto the surface of the tantalum with or without an the alloying step. The second deposition produces a spongy layer and is accomplished by conventional electrolytic techniques.

Abstract: An anti-stall motor drive circuit for a very slow running permanent magnet d.c. motor is disclosed. The slow running speed of the motor sometimes allows an insulating film to build up between the brushes and the commutator which causes the stalled condition. The motor (10) is connected in the collector circuit of a drive transistor (Q1) which has a current limiting resistor (R9) connected in its emitter circuit. A stalled condition of the motor (10) is sensed by a lack of output from a tachometer (16) output. The output of the tachometer is full wave rectified by an operational amplifier (22) and diodes (CR1 and CR2). The rectified tachometer voltage is applied to an integrator (24 and C1) having a clamping diode (CR7) connected in its feedback circuit. A zero output from the rectifier allows the integrator output to ramp up to a limiting value determined by the clamping diode.

Abstract: An innput/output terminal assembly for pressure transducers of the flexure type. The transducer includes a flexure member which senses an applied pressure by means of strain gauges mounted thereon. A known problem with such an arrangement concerns the electrical connections to the strain gauges wherein there is conflict between the flexible connections required to accommodate flexure displacement and the rigid connections required to lead away from the gauges since a pressure chamber must be spanned. Previously this conflict has been resolved by bonding an insulative terminal plate proximate the flexure to provide a junction between flexible and rigid conductors. Such an arrangement gives rise to problems of construction rigidity and performance if excess bonding resin contacts the flexure. The invention provides a welded terminal plate, which is insulative by virtue of a thick film layer of glass, on which electrical connection may be made to areas of thick film gold.

Abstract: An overvoltage protection circuit limits the output voltage of a DC to DC converter to a maximum desired output voltage. An output voltage sensing circuit includes a semiconductor device such as a sidac having a normal resistive region of operation as well as a negative resistance region of operation which begins at a breakover voltage and extends into a foldback region. One terminal of the sidac is coupled to sense the converter output voltage while the second terminal opposite end of the sidac is coupled to a biasing device in the form of a resistor which generates an overvoltage signal when the sidac conducts current. The overvoltage signal from the biasing resistor is coupled to a converter switching transistor disabling circuit which reduces the converter output voltage to a level below the maximum desired output voltage in response to the overvoltage signal.

Abstract: An automatic changer for cassette tapes suited for the use in an automobile or the like constituted of a tape container capable of containing a plurality of cassette tapes and a table for supporting the tape container. The tape container is provided with a first engagement portion extended in the direction orthogonal to the direction in which the cassette tape is inserted into the tape container and the table is provided with a second engagement portion which engages the first engagement portion. The first engagement portion is positioned out of the center of the side plate of the tape container which is disposed in parallel with the direction in which the cassette tape is inserted and adapted to be movable relative to the second engagement portion.

Abstract: An electrical contact having a compliant section for mounting the contact on a circuit board in a plated-through hole. The compliant section includes a section having a configuration which deforms upon insertion into the circuit board hole and creates positive electrical contact at three points. The contact may include a wire wrap tail and an upper pin or post to mate with a connector.

Abstract: A method of making an electrical contact intended to be inserted into a plated-through hole in a printed circuit board including a compliant section which engages the inside of the hole in an interference fit thereby gripping the sides of the hole to retain the pin therein providing excellent electrical integrity without need for soldering.

Abstract: The DC to DC converter includes a coupled inductor having a primary winding and a feedback winding. A drive current regulator circuit receives a variable input voltage from the feedback winding but transmits a constant base drive current to the base terminal of the converter switching transistor. The base drive regulator circuit thereby enables the DC to DC converter to operate at high levels of efficiency over wide ranges of DC input voltages such as twelve to forty-eight volts DC.

Abstract: A debris detector for a particle counter, such as a blood cell counter, of the COULTER (R) type. When a particle, or transient debris, passes through the sensing orifice of the particle detector, a voltage pulse occurs; whereas, when debris lodges in or against the orifice of the particle detector, a d.c. voltage shift occurs. The voltage at the orifice is capacitively coupled to an amplifier and the output of the amplifier is integrated. The capacitor coupling the orifice voltage to the amplifier causes an undershoot voltage at the trailing edge of each particle or transient debris pulse, such that a zero average voltage is applied to and, hence, from the amplifier for each voltage pulse. The integrated voltage is applied to a voltage comparator to provide an output signal therefrom whenever the integrated voltage exceeds a reference voltage. The comparator output signal is provided to a delay circuit having a delay related to the time required for a particle to pass through the COULTER detector orifice.

Abstract: A common remote control device has an operating section for specifying an equipment to be remote-controlled and an operation of the equipment; a memory; a receiving unit for receiving various remote control signals generated from each of the private remote control transmitters provided corresponding to the equipment; a control unit for storing the remote control signals corresponding to each operation of the equipment as digital data in the memory, and retrieving the data from the memory to generate same; and a regeneration unit for regenerating the remote control data generated from the control unit and supplying a regenerative remote control signal to the equipment specified by the operating section. All of the equipment may be remote-controlled by a single remote control transmitter used to access the remote control device.

Abstract: A printed wiring board is made up of an insulating board and a conductor pattern, which has a plurality of lands, disposed on the insulating board and provided with a solder-resist layer formed on the conductor pattern excluding the lands. Solder-resist barriers are disposed on the solder-resist layer in between the lands with the top surface thereof built to a higher level than the surface level of the lands for effectively preventing formation of a solder bridge between adjoining lands.

Abstract: The battery charger includes a slope detector which responds to the battery voltage of the battery being charged, to generate a peak indicating signal, when the voltage decreases following the peak charging voltage of the battery. A peak hold device responds to the peak indicating signal to cause the charger to switch abruptly from a high charge mode to a low trickle charge mode.

Abstract: An electroluminescent panel and method of making the same includes a plurality of layers on a transparent electrode in which each layer is formed with the same compatible polymer carrier resin base material so that the individual layers have an integrated uniformity. A polyester laminating resin is disclosed for the resin base material of each layer which is activated by a small amount of diisocyanate sufficient to provide temperature stability, but insuffient to transform the base material into a urethane. Also disclosed is an electroluminescent lamp which emits light only in discrete areas such as to produce a pattern of light in which the phosphor is applied in a pattern corresponding to the discrete areas which are to be illuminated. Similarly, the electrodes are restricted to the illuminated regions or areas, thereby conserving material as well as reducing the power requirements of the lamp.

Abstract: A high-voltage cylindrical film-type resistor has cup-shaped end caps that receive the ends of the cylindrical substrate, each end cap having a convexly-radiused rim that has a radius of at least 1.5 mils in a plane containing the substrate axis. In accordance with the method, the stated radius is achieved by abrading, preferably tumbling.