Patents Examined by Lawrence J. Dahl
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Patent number: 3973214Abstract: A circuit comprising the first stage of a multi-stage amplifier is described, incorporating a plurality of networks connected between the input stage transistor emitter and ground. The networks are connected in parallel; each comprises a series resonant circuit, the resonant frequencies and component values of which have been chosen to provide wideband impedance-matching to the base of the transistor while achieving a low noise figure.Type: GrantFiled: January 20, 1975Date of Patent: August 3, 1976Assignee: Alpha Engineering CorporationInventor: William A. Rheinfelder
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Patent number: 3973215Abstract: A current mirror amplifier circuit with an input current path and an output current path is further provided with a sensing means responsive to the cessation of current flow in the output current path such that the cessation of current flow in the output current path causes the current flow in the input current path to be discontinued.Type: GrantFiled: August 4, 1975Date of Patent: August 3, 1976Assignee: RCA CorporationInventor: Adel Abdel Aziz Ahmed
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Patent number: 3972004Abstract: The charge preamplifier comprises an input stage driven by the signal to be amplified, the input stage being connected to an amplification stage associated with an output stage, and a circuit for applying optoelectronic feedback from the output to the input of the preamplifier. The input stage comprises a cooled field-effect transistor, the signal to be amplified being applied to the input gate of the transistor. The load resistance of the transistor is provided by a second field-effect transistor mounted in series with an inductance coil.Type: GrantFiled: November 26, 1974Date of Patent: July 27, 1976Assignee: Commissariat a l'Energie AtomiqueInventor: Gerard Libs
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Patent number: 3972003Abstract: A relatively high sensitivity and high speed current detector consists of essentially a common base differential amplifier consistng of two junction transistors, each having separate emitter and collector resistors, and a constant current source connected to the collector resistors. Separate input terminals connected to the emitters allow complementary information current signals or an information current signal and a reference current signal to be applied to the emitter terminals. The output signal and the complement thereof appear at their respective collectors.Type: GrantFiled: August 9, 1974Date of Patent: July 27, 1976Assignee: Bell Telephone Laboratories, IncorporatedInventor: Paul Robert Schroeder
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Patent number: 3972006Abstract: An active filter for electronic circuits comprising a single frequency bandpass filter including two stages each comprising a differential input high performance operational amplifier with the output of a second stage being connected in feedback relationship to one input of the first stage and the output of the first stage being interconnected with one input of the second stage. The output of the filter circuit is taken from the output of the first stage of the amplifier and the input to the filter circuit is the negative input of the first stage of the amplifier.Type: GrantFiled: September 20, 1974Date of Patent: July 27, 1976Assignee: Beckman Instruments, Inc.Inventor: Frank A. Ruegg
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Patent number: 3970949Abstract: 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.Type: GrantFiled: November 19, 1974Date of Patent: July 20, 1976Assignee: Oki Electric Industry Company, Ltd.Inventor: Michio Higuchi
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Patent number: 3970951Abstract: 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.Type: GrantFiled: November 12, 1975Date of Patent: July 20, 1976Assignee: International Business Machines CorporationInventor: Charles Reeves Hoffman
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Patent number: 3970948Abstract: 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.Type: GrantFiled: December 6, 1974Date of Patent: July 20, 1976Assignee: RCA CorporationInventors: Leopold Albert Harwood, Erwin Johann Wittmann
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Patent number: 3970950Abstract: A dual channel high gain differential amplifier utilizing enhancement depletion MOS field effect transistors which exhibits high common mode rejection and fast switching characteristics.Type: GrantFiled: March 21, 1975Date of Patent: July 20, 1976Assignee: International Business Machines CorporationInventors: Leo B. Freeman, Jr., Robert J. Incerto, Joseph A. Petrosky, Jr.
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Patent number: 3970947Abstract: 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.Type: GrantFiled: May 21, 1975Date of Patent: July 20, 1976Assignee: Tokyo Shibaura Electric Co., Ltd.Inventors: Itsuzo Sato, Kikuo Saito
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Patent number: 3970886Abstract: 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.Type: GrantFiled: November 2, 1973Date of Patent: July 20, 1976Assignee: Owens-Illinois, Inc.Inventors: Wolfgang W. Bode, Michael E. Fein, David C. Hinson
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Patent number: 3970871Abstract: 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.Type: GrantFiled: February 19, 1974Date of Patent: July 20, 1976Assignee: GTE Automatic Electric Laboratories IncorporatedInventor: Neale A. Zellmer
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Patent number: 3969650Abstract: 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.Type: GrantFiled: November 27, 1974Date of Patent: July 13, 1976Assignee: Zenith Radio CorporationInventors: Gerald Joseph Chodil, Michael C. DeJule, David Glaser
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Patent number: 3969679Abstract: 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.Type: GrantFiled: July 26, 1974Date of Patent: July 13, 1976Assignee: General Electric CompanyInventor: Charles W. Sexton
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Patent number: 3968397Abstract: The invention concerns a firing device for a number of electric valves, particularly thyristors. Each thyristor control path is associated with a firing circuit with a detector for electromagnetic radiation responsive to a transmitter which is controlled by a firing control signal and is equipped with a radiating device which energizes the individual detectors. To transmit the firing control signal with sufficient strength, a transmitter with a radiator is provided which is arranged in the focal line of a reflector designed as a partial elliptical cylinder. The individual detectors are disposed in a line which is aligned essentially parallel to the focal line of the reflector.Type: GrantFiled: December 5, 1974Date of Patent: July 6, 1976Assignee: Siemens AktiengesellschaftInventors: Stefan Frese, Franz Mayerhofer
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Patent number: 3968399Abstract: Methods of driving a light-emitting diode (LED) or an injection diode at very high digital data rates using high speed emitter coupled logic (ECL) gates.Type: GrantFiled: March 19, 1975Date of Patent: July 6, 1976Assignee: The United States of America as represented by the Secretary of the NavyInventor: Bobby R. Jarrett
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Patent number: 3968400Abstract: A flash tube modulator circuit having a high peak power output at a high etition rate (50 KC) with variable pulse widths by employing resonant charging and discharging to ionize the gas in a flash tube followed by a high current pulse to produce a high peak power output.Type: GrantFiled: March 30, 1965Date of Patent: July 6, 1976Assignee: The United States of America as represented by the Secretary of the NavyInventor: Wayne C. Weinreich
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Patent number: 3968453Abstract: A signal to be controlled is applied to the base of an emitter-follower input transistor, the emitter of which is connected to an input terminal of a differential amplifier. This input terminal of the amplifier is connected by a diode to a controllable current source so that the base current of the differential amplifier input transistor is controlled. A constant current source is connected to the common emitter circuit of the differential amplifier, and the gain of the circuit is determined by the ratio of current in the latter source to current in the controllable source.Type: GrantFiled: December 2, 1974Date of Patent: July 6, 1976Assignee: Sony CorporationInventors: Masayuki Hongu, Tsutomu Niimura
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Patent number: 3967158Abstract: A bar graph display panel comprises a gas-filled envelope containing a series of fine, closely-spaced cathode lines connected in groups so that they can be energized sequentially and individually. The panel also includes an anode film supported on the face plate and aligned with and in operative relation with the series of cathode lines. The anode and cathodes are closely spaced and the panel contains an ionizable gas at relatively high pressure.In order to use the display panel to display a bar of light, the anode and cathodes are connected in an operating circuit wherein each of the cathodes is energized or scanned and caused to glow sequentially. An analog signal to be displayed as a bar of light and a ramp signal are coupled to a comparator, the output of which energizes the anode electrode.Type: GrantFiled: January 24, 1975Date of Patent: June 29, 1976Assignee: Burroughs CorporationInventor: Richard A. Saxon
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Patent number: 3965437Abstract: A microwave semiconductor amplifier or oscillator system in which a semiconductor device has an avalanching region at a junction and a heat sink having a higher thermal conductivity than said avalanching region in close thermal contact with the said junction. The avalanching region has a width substantially less than ten times the thickness of said avalanching region but a length substantially greater than said width. The heat sink is made substantially wider than that of the avalanching region so that heat generated in the avalanching region during operation of the system and moving into the heat sink will have a substantial component thereof moving parallel to the junction, thereby decreasing the thermal resistance between the heat source and the heat sink and hence permitting an increased power output from the system.Type: GrantFiled: August 26, 1974Date of Patent: June 22, 1976Assignee: Raytheon CompanyInventor: Chung Kyu Kim