Patents Examined by John Zazworsky
  • Patent number: 5138205
    Abstract: The invention pertains to electrical power control more particularly to a class of circuitry known as thyristor phase control. The novel circuit can be used to control heating devices, electrical motors and generators and many other types of equipment that require a precise control of the output of a thyristor.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: August 11, 1992
    Inventor: Paul L. Herbert
  • Patent number: 5136183
    Abstract: There is disclosed a three-state buffer including a comparator circuit which comprises a plurality of bipolar transistors and which generates first and second control voltages which are dependent upon the forward biased base to emitter voltage drops of the transistors. The comparator circuit also includes a threshold circuit establishing a threshold voltage intermediate the first and second control voltages which is also dependent upon the forward biased base to emitter voltage drops of the transistors. As a result, the threshold voltage is always intermediate the first and second control voltages to assure reliable operation of the comparator circuit notwithstanding variations in integrated circuit processing parameters or integrated circuit operating temperatures.
    Type: Grant
    Filed: June 27, 1990
    Date of Patent: August 4, 1992
    Assignee: Advanced Micro Devices, Inc.
    Inventors: Miki Moyal, Russ Apfel
  • Patent number: 5136184
    Abstract: A comparator for use in an A/D converter such as an algorithmic type. The circuit includes a push-pull inverter gain stage having two series-connected MOSFETs. The input of this inverter is driven by a signal from a preceding current-comparison stage where an input current is compared to a reference current to set the signal level on an input node of the inverter. The trigger point of the inverter is altered by an additional MOSFET, connected in parallel with one of the inverter MOSFETs, and having its gate controlled by the output of a bias voltage control circuit. This circuit includes a control inverter stage matched to the comparator inverter and driven by a control current-comparison circuit matched to the corresponding comparator current-comparison circuit.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: August 4, 1992
    Assignee: Analog Devices, Incorporated
    Inventor: Kenneth Deevy
  • Patent number: 5134309
    Abstract: A preamplifier providing adequate boost even to weak and small input currents, and thus achieving favorable gain and signal-to-noise ratio. An input current is converted to a voltage, which is provided to a differential amplification section. A phase-adjusted version of that voltage signal also is provided to the differential amplifier, the differential amplifier thus outputting an amplified signal based on the phase difference between its inputs. The preamplifier may be incorporated on a single chip, using MOS transistors or gallium arsenide techniques. A level clamping device may be provided in the event that the input current exceeds a predetermined value. The inventive preamplifier also may be incorporated advantageously into a waveform shaping circuit.
    Type: Grant
    Filed: June 7, 1990
    Date of Patent: July 28, 1992
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Motoaki Matsumoto, Hideaki Kimura
  • Patent number: 5132558
    Abstract: A recycling ramp interpolator is described which can provide multiple measurements for a single input trigger signal by maintaining initial input waveform reference and interpolating multiple times before completely discharging. The interpolator reference voltage can be changed to provide effective sampling intervals of fractions less than one of the clock period.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: July 21, 1992
    Assignee: Hewlett-Packard Co.
    Inventor: David J. Rustici
  • Patent number: 5128566
    Abstract: A current controlled variable attenuator circuit using a current controlled resistor is disclosed. In paticular, the current controlled resistor and attenuator are particularly suited for use in hearing aids due to the resistor's and attenuator's easy implementation in bipolar integrated circuits. The current controlled resistor and attenuator also has wide application to other circuitry requiring controlled variable resistance elements having a broader linear response than previously available. The current controlled resistor consists of transistors having inherent non-linear characteristics which can be linearized by adding appropriate compensation circuitry.
    Type: Grant
    Filed: November 3, 1989
    Date of Patent: July 7, 1992
    Assignee: Etymotic Research, Inc.
    Inventors: Mead C. Killion, Donald L. Wilson
  • Patent number: 5126589
    Abstract: A drive circuit for use with a capacitive load includes two transistors controlled by a drive voltage and connected to the load through an inductor. A supply voltage is alternately connected and disconnected to the circuit to achieve a resonant transfer of energy from the supply voltage. Energy stored in the load is transferred to the inductor and then back to the load, thereby reversing and augmenting the output voltage across the load and providing an instantaneous output voltage many times the supply voltage. Diodes ensure that the current flows in the proper polarity through the transistors.
    Type: Grant
    Filed: August 31, 1990
    Date of Patent: June 30, 1992
    Assignee: Siemens Pacesetter, Inc.
    Inventor: Herman L. Renger
  • Patent number: 5126864
    Abstract: A ferroelectric liquid crystal panel comprising 2 layers of liquid crystal cells, each of which comprises a ferroelectric crystal sealed between two substrates and then is laminated together; wherein one of said liquid crystal cells is operated as a panel driving liquid crystal cell and the other of said liquid crystal cells is operated as an optical compensating cell, while both said liquid crystal cells being driven by rectangular wave AC signals. Furthermore, the ferroelectric liquid crystal panel is constructed to operate in an intermediate tone by varying the phases of said rectangular wave AC signals applied to the liquid crystal cells of the first and second layers.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: June 30, 1992
    Assignee: Stanley Electric Company
    Inventors: Ryouichi Akiyama, Kazuhisa Ui, Koutaro Yoneda, Masafumi Ide
  • Patent number: 5126588
    Abstract: A digital push-pull driver circuit comprising two output transistors which are alternatingly controlled into the conducting state by a data control circuit and to whose common connection point a load to be driven is connected. One slope steepness reducing, enable-dependent delay circuit each is connected between the control electrode of each of the two output transistors and the data control circuit. The output of each delay circuit is connected to an enable input of the respective other delay circuit. The delay times of the two delay members are at least as long as the width of the steepness-reduced pulse slopes in terms of time.
    Type: Grant
    Filed: January 16, 1990
    Date of Patent: June 30, 1992
    Assignee: SGS-Thomson Microelectronics GmbH
    Inventors: Hans Reichmeyer, Josef Stockinger
  • Patent number: 5124583
    Abstract: A DC powered integrated circuit includes a plurality of magnetic flux coupling type Josephson elements. First and second Josephson elements are connected in series to form a first element series circuit of Josephson elements. Third and fourth Josephson elements are connected in series to form a second element series circuit of Josephson elements. The first and second element series circuits are connected in series to form a huffle circuit, with a load inductance, three resistors and a DC current source.
    Type: Grant
    Filed: February 5, 1991
    Date of Patent: June 23, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Yuji Hatano, Shinichiro Yano, Hiroyuki Mori, Hirozi Yamada, Mikio Hirano
  • Patent number: 5122695
    Abstract: A SCR (silicon controlled rectifier) control circuit using two pulses to turn-on and turn-off the SCR, the time of turn-on and turn-off being selectively controlled.
    Type: Grant
    Filed: July 24, 1989
    Date of Patent: June 16, 1992
    Inventor: Chao-Cheng Lu
  • Patent number: 5120996
    Abstract: An electronic circuit is disclosed having a sample/hold amplifier connected to an adaptive amplifier. A plurality of such electronic cicuits may be configured in an array of rows and columns. An input voltage vector may be compared with an analog voltage vector stored in a row or column of the array and the stored vector closest to the applied input vector may be identified and further processed.
    Type: Grant
    Filed: June 6, 1990
    Date of Patent: June 9, 1992
    Assignee: Synaptics, Incorporated
    Inventors: Carver A. Mead, Federico Faggin, Timothy P. Allen, Janeen D. W. Anderson
  • Patent number: 5118966
    Abstract: A detection voltage output circuit of a charge generation type sensing device outputs the charges generated on the sensing device in the form of a voltage.
    Type: Grant
    Filed: July 3, 1991
    Date of Patent: June 2, 1992
    Assignee: Murata Mfg. Co., Ltd.
    Inventor: Akira Kumada
  • Patent number: 5115153
    Abstract: An integrated semiconductor circuit made up of a differential stage which comsists of a differential pair of field effect transistors (10, 11) having outputs (34, 35) which are coupled to the inputs of an output stage or sub-circuit (31, 32, 51, 52) for controlling same, and also including a load circuit (R.sub.4, R.sub.3). The circuit provides smoothing means for smoothing fluctuations of an output impedance of the differential transistor pair (10,11) during switching thereof.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: May 19, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Thierry Ducourant
  • Patent number: 5115151
    Abstract: A comparator which is used to compare two analog voltages and provide a single ended output comprises three CMOS differential amplifiers. The use of three differential amplifiers provides improved matching of input capacitance, and a reduction in propagation delay over prior art use of a single differential amplifier. The comparator may be adopted for use in certain CMOS processes to extend the maximum operating voltage by limiting the internal node voltages otherwise subject to damage from impact ionization. An alternative embodiment is disclosed for comparing two analog voltages that are outside the power supply voltage range.
    Type: Grant
    Filed: June 8, 1990
    Date of Patent: May 19, 1992
    Assignee: Western Digital Corporation
    Inventors: Richard W. Hull, Timothy G. O'Shaughnessy
  • Patent number: 5115156
    Abstract: An apparatus for triggering a plurality of thyristor devices includes a full-wave rectifier circuit having a sinusoidal pulse output, a Schmitt trigger circuit to generate a constant amplitude pulse signal when the sinusoidal pulse output exceeds a certain triggering level, a clock pulse generator to generate a predetermined number of clock pulses within the duration of the constant amplitude pulse signal, and an address counter to receive the generated clock pulses. The address counter has a digital output corresponding to the number of clock pulses received. A read-only memory unit has digital data stored therein. The memory unit has a plurality of address lines to receive the digital output of the address counter and a set of output data bits corresponding to the stored digital data which is accessed according to the digital output of the address counter. Each thyristor device is triggered into the conducting state by one of the output data bits of the memory unit.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: May 19, 1992
    Inventor: Huai-Chou Tsui
  • Patent number: 5113090
    Abstract: A voltage comparator is provided including a differential amplifier, first, second and third switches, and first and second capacitors. A fourth switch is connected in series between the second and third switches and an input terminal of the differential amplifier. A first input voltage is sampled and held at the first capacitor through the first switch and at the second capacitor through the second and fourth switches, respectively. Thereafter, since the third switch is turned on and the fourth switch is turned off, the first input voltage is sampled and held at the input capacitor of the differential amplifier. Thereafter, the third switch is turned off and the fourth switch turned on. As a result, an on and off operation of the fourth switch is controlled so that a second input voltage which has been sampled at the second capacitor immediately before the switch is turned off is applied to the input capacitor of the differential amplifier.
    Type: Grant
    Filed: August 29, 1990
    Date of Patent: May 12, 1992
    Assignees: Hitachi Ltd., Hitachi VLSI Engineering Corporation
    Inventors: Eiki Imaizumi, Kunihiko Usui, Tatsuji Matsuura, Toshiro Tsukada, Seiichi Ueda, Hiroshi Sato
  • Patent number: 5113089
    Abstract: A sensing circuit is disclosed wherein a first MOS transistor is connected in series with a load to produce a source to drain voltage in response to the load current. A reference voltage generating circuit includes a second MOS transistor and provides a reference voltage determined by the source-to-drain voltage of the second MOS transistor in response to a constant current supplied thereto. A comparator circuit compares the source to drain voltage of the first MOS transistor with the reference voltage to sense the load current.
    Type: Grant
    Filed: August 29, 1990
    Date of Patent: May 12, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yasuo Osawa
  • Patent number: 5113091
    Abstract: An amplifier includes an input circuit for alternately selecting input signals to be compared and a first bias circuit for producing self-bias when one of the input signals is selected. A second bias circuit stores the self-bias for use in the amplifier when the other of the input signals is selected for rejecting noise which may accompany power supply voltage applied to the amplifier.
    Type: Grant
    Filed: March 19, 1991
    Date of Patent: May 12, 1992
    Assignee: Texas Instruments Incorporated
    Inventors: Wei-chan Hsu, William R. Krenik
  • Patent number: 5113085
    Abstract: A circuit arrangement is described for supplying a load (1) from a direct voltage source (14) through a switch bridge (3 to 6), by which the direct voltage source (14) can be connected in alternating polarity to the load (1), comprising a control circuit (17) for controlling the switch bridge (3 to 6); and including a circuit for precisely adjusting and controlling a given D.C.
    Type: Grant
    Filed: August 23, 1990
    Date of Patent: May 12, 1992
    Assignee: U.S. Philips Corporation
    Inventors: Ralf Schafer, Armin Wegener