Abstract: A magnetism detecting system, in which reference magnetic fields sequentially scan many radial scanning lines obtained by dividing a plane to be detected at regular intervals of a desired angle with respect to an origin positioned at the common intersecting point of said scanning lines. At least one parametrically excited second harmonic oscillator detects the direction and magnitude of a magnetic field to be detected along each of the scanning lines. A display device is provided for scanning and displaying the plane with respect to the origin in synchronism with the scanning of each of the scanning lines. A detected output is applied to the display device when the magnetic field to be detected and the reference magnetic field coincides with each other in direction and in magnitude.

Abstract: Apparatus for indicating the charge condition of a secondary cell, comprising an integrating device which progressively sums the ampere-hours drawn from the cell, and a computer which is programmed to provide a voltage output whose magnitude indicates the total number of ampere-hours available, from the battery at the particular discharge current and temperature. A comparator subtracts from this a voltage derived in accordance with the output of the integrating device. The comparator output thus indicates the remaining ampere-hours available to be drawn from the cell at the prevailing conditions of discharge current and temperature. There may be provided a further computer which is programmed in accordance with the variation in minimum ampere-hour requirement of the cell to ensure that a particular load, e.g. a starting motor, can be successfully operated at various temperatures.

Abstract: The disclosed circuit provides a wideband, wide-range logarithmic responding voltmeter particularly suitable for use as a transducer analyzer. The circuit includes an input for receiving a given A.C. input signal which can vary within a 100 db dynamic range. The input signal is coupled to a buffer amplifier the output of which is capacitively coupled to a logarithmic converter. The converter includes an operational amplifier and provides an A.C. output signal which is proportional to the logarithm of its A.C. input signal. The open loop gain of the operational amplifier is utilized to provide the A.C. output signal. The output signal of the converter is capacitively coupled to a precision AC/DC converter which rectifies and filters the output signal to provide a D.C. output voltage the level of which is, therefore, also proportional to the logarithm of the given A.C. input signal within its 100 db range. The D.C.

Abstract: The subject of this invention is a differential amplifier circuit having a constant gain characteristic over a range of input voltage and suitable for use in integrated circuits in semi-conductor chips. The circuit is embodied in the enhanced-depleted field effect transistor technology and includes a pair of parallel circuits. Each circuit has a depletion type of field effect transistor (FET) connected to the drain voltage source, and its source connected to the drains of two enhanced FET's and to the gate of the one of these which has its source to a ground level. The other enhanced FET's have their sources connected together and to a constant current source. One gate of these other FET's is connected to the reference voltage and the other to an input voltage to be amplified. By a proper selection of FET design parameters, the amplifier gain can be constant over the full operating range of the input voltage.

Abstract: There is disclosed a multiple gaseous discharge device containing at least one insulated electrode, an ionizable gaseous medium, and a multiplicity of gas discharge cells, the gaseous medium having incorporated therein at least one selected gaseous component which emits high intensity ultraviolet radiation upon appropriate excitation such that the gaseous discharge device has improved photon conditioning. Preferably the gas additive is selected from mercury, xenon, and krypton.

Abstract: A dual channel high gain differential amplifier utilizing enhancement depletion MOS field effect transistors which exhibits high common mode rejection and fast switching characteristics.

Abstract: The heat-transfer capability of a movable-electrode gas-filled arc lamp is optimized. In the preferred embodiment, the movable electrode is the anode which is mounted at the base of the lamp coaxialy with and spaced apart from the cathode. Low-voltage starting of the lamp is provided by solenoid means for moving the anode briefly into contact with the cathode and then withdrawing the anode from contact with the cathode so that a difference of electrical potential develops between the cathode and the anode, which is sufficient to ionize the gas in the gap formed therebetween. The arc thereby generated in the gap follows the withdrawing anode to its fully spaced-apart position with respect to the cathode. A heat sink member is disposed within the gas-filled envelope at the base of the lamp, and a metal collar is affixed to and surrounds the movable anode. The collar provides thermally conductive contact with the heat sink member when the anode is in its fully spaced-apart position with respect to the cathode.

Abstract: A method and an apparatus are described for indicating and/or recording electrical quantities, the desired and actual values being converted into pulses whose repetition frequencies are proportional to the actual and desired quantities. The difference between the two pulse frequencies controls a stepping motor, whose shaft drives the indicating or recording element.

Abstract: A multi-stage differential amplifier circuit comprises a preceding stage differential amplifier and a succeeding stage differential amplifier which are direct-coupled in unbalanced configuration. A variation in the DC level at an output of the amplifier circuit due to the temperature drift of a constant current source transistor in the preceding stage differential amplifier is compensated by a bias circuit connected to the base of one of differential transistors in the succeeding stage differential amplifier. The compensation bias circuit includes a current source transistor the base of which is connected, together with the base of the current source transistor in the preceding stage differential amplifier, to a common drive voltage source.

Abstract: The invention relates to the supervision of a measuring circuit which is connected to a load by way of measuring leads. This load is connected to a generator via supply leads. The load is bridged by a resistor. If one of the four said leads is interrupted, the potential on one of the ends of the resistor changes. As a result, a transistor becomes conductive, which implies an error signal. In a preferred embodiment, two transistors are provided, the first transistor being rendered conductive by a voltage difference. The second transistor is rendered conductive either by a voltage difference or by the fact that the first transistor becomes conductive.

Abstract: A direct current power supply is capable of delivering up to 1 ampere at 60 to 80% power efficiency from a storage battery source, providing a positive DC power output free from inductor-generated type switching transients. The converter embodies a regenerative switching mode means which alternately drives two sets of paired power transistors, turning on each one pair of power transistors for one-half cycle. Each one of the power transistor pair alternately transfers electron charges to a first one of two switch-coupled capacitors, thence to the second one of the two capacitors, and then to a positive voltage terminal. RC clipping circuitry is coupled to each one of the pair of power transistors providing faster resetting times for the power transistors, increasing the converter power efficiency by decreasing storage-time delay. By decreasing power transistor direct shorting time during power transistor switching between transistor pairs, power loss is decreased.

Abstract: There is disclosed a printed circuit board test fixture which comprises a housing, a pair of parallel, opposed platens with press means associated with at least one of the platens. One of the platens supports a printed circuit board and the other supports a plurality of spring-biased, probe contact units positioned at predetermined locations to make contact to selected points of the printed circuit board when the platens are pressed into registration. When the contact units are carried in a removeable probe head which is one of a plurality of interchangeable probe heads, the test fixture can support an interface connector in substantially parallel alignment to the platens and the probe head bears interface contact members which are moved into mating connection with opposite interface contact members carried by the interface connector.

Abstract: A signal amplifier is supplied with input signals at its base electrode and also is supplied at its emitter with quiescent operating current from a current source. Amplified output signals developed at the collector of the amplifier are coupled to a transistor-diode current splitter. The relative division of current in the splitter is controlled by coupling a variable direct current supply to the diode. The latter supply comprises a source of direct voltage, a variable, resistive voltage divider coupled across the voltage source, and the combination of a voltage follower stage and a series resistor coupled between the resistive divider and the diode. Gain controlled push-pull output signals may be provided by differentially coupling a second amplifier device to the first and coupling the output of a second current splitter to the second amplifier. The second current splitter is then also controlled by the same current source as the first.

Abstract: In the disclosed electron gun positive ions generated by a hollow cathode plasma discharge in a first chamber are accelerated through control and shield grids into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode causing the cathode to emit secondary electrons which form an electron beam having a distribution adjacent to the cathode emissive surface substantially the same as the distribution of the ion beam impinging upon the cathode. After passing through the grids and the plasma discharge chamber, the electron beam exits from the electron gun via a foil window. Control of the generated electron beam is achieved by applying a relatively low control voltage between the control grid and the electron gun housing (which resides at ground potential) to control the density of the positive ions bombarding the cathode.

Abstract: A Hall voltage device including means for generating a magnetic field and a rotatable box mounted within the field in the air gap defined by the means. The box is arranged to receive a fluid including charged particles and comprises appropriately located electrodes cooperating with the fluid and means for rotating the box. An end face of the box is provided with a central aperture around the axis of rotation for introducing the fluid into the box. In another embodiment the apparatus comprises a pivot having two parts, each part connected to a respective electrode of the box. Each part contacts an amount of mercury contained in a reservoir. The two reservoirs are connected to a voltage meter. Cooling means for the mercury reservoir is also disclosed.

Abstract: A digital tachometer for generating electrical pulses at a rate indicative of the speed of rotation of a shaft-like member. A first toothed disk having N teeth is affixed to the shaft and a housing having a second set of M teeth is fixed with respect to the shaft and positioned around the toothed disk. As the shaft rotates, individual ones of the teeth on the outer periphery of the disk which is affixed to the rotating shaft alternatively pass into and out of close proximity to individual ones of the teeth of the outer housing resulting in periodic increases and decreases in the reluctance of the system. A sensing coil is positioned with respect to the housing so as to generate an electrical current which varies as the reluctance changes from one polarity to another as the shaft rotates.

Abstract: A high-frequency automatic gain control circuit for a common emitter earthed amplifier wherein a hybrid negative feedback is applied to an input stage thereof from the emitter of an output stage transistor through a hybrid transformer connected to the base of an input stage transistor and a series negative feedback is applied to the output stage thereof, and according to the present invention a diode which is shunted by a capacitor is connected in series to an emitter resistor of the output stage transistor, and an automatic gain control signal is applied to said diode for regulating the gain of said amplifier by controlling negative feedback ratio of said negative feedback.

Abstract: A highly efficient, high current density gas discharge display panel having rows of columns of gas discharge cells. Each row and discharge cells communicates with a row of hollow cathodes formed of row-wise extending front and rear cathode means positioned adjacent and essentially parallel to each other. When a forward and rear cathode means are both energized, they operate together to form a row of hollow cathodes. With only the forward cathode means energized, a low current gas discharge exists in a row of cells, which discharge is transferred to the next adjacent row of cells by the application of scanning signals to the forward cathode means. A simplified unitary center sheet houses the cell enclosures and grooves for anode and cathode conductors to eliminate the need for multiple layers which require registration with one another. The novel structure permits a fast scan rate and efficient priming of the cells to avoid the necessity for high voltage video drivers.

Abstract: A biasing circuit for a complementary symmetry transistor amplifier utilizing a control transistor is disclosed in which the base terminal of the control transistor is connected to the base terminal of one of the complementary transistors so that the bias current drawn by the amplifier transistors is the control current for the control transistor. A bias voltage establishing network includes one element connected between the emitter and collector terminals of the control transistor so that the bias voltage is coupled via the emitter-base junction of the control transistor to the complementary transistors and thus the bias current drawn by the complementary symmetry amplifier determines the degree of conduction of the control transistor and therefore the bias voltage applied to the amplifier. In this manner sufficient bias voltage is applied to the amplifier to maintain conduction to avoid crossover distortion and at the same time the current drawn by the amplifier is limited to prevent thermal runaway.

Abstract: A single probe voltmeter for determining the voltage potential of high voltage transmission lines is disclosed. The voltmeter includes a capacitor having a spherical first plate connected to the transmission line through a rectifier network. The second plate of the capacitor is formed by the physical surroundings. An ammeter is connected across the rectifier network to provide an indication of the charging current for the spherical capacitor, which charging current is essentially a function of the transmission line voltage such that the ammeter provides an indication of the voltage potential on the transmission line.