Potentiometer Common To Signal And Feedback Path Patents (Class 330/108)
  • Patent number: 8063697
    Abstract: A self-oscillating driver circuit comprises a driver stage, a feedforward path which is coupled to an input of the driver stage, and a feedback path which couples an output of the driver stage to an input of the feedforward path. The feedforward path comprises a feedforward filter which is designed as an active filter. In order to prevent an oscillatory state of the driver circuit at an unwanted frequency, it is proposed that an internal state variable of the feedforward filter be monitored and that the feedforward filter be reset if the value of the monitored internal state variable is outside a predefined range.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: November 22, 2011
    Assignee: Lantiq Deutschland GmbH
    Inventors: Dario Giotta, Thomas Poetscher, David San Segundo Bello, Andreas Wiesbauer
  • Patent number: 5705951
    Abstract: In a method and by an apparatus for correction of error signals and for forming of an arbitrary transfer function being independent of the quality of a payload (loudspeaker; H1) included in a signal amplification system, a control system (9) is used for supplying of the input signal to a basic amplifier (1) driving the payload. Said control unit includes a further amplifier (9) having an inverted input being supplied with a feedback signal from the output of the basic amplifier. In such a case the further amplifier involves only an inverted input, said input signal is supplied through one (4) of the resistors (3, 4) included in the feedback loop.
    Type: Grant
    Filed: December 23, 1996
    Date of Patent: January 6, 1998
    Inventor: Bjarne H.ang.kansson
  • Patent number: 5371472
    Abstract: A charge amplifier for sensors outputting electrical charge, particularly for piezoceramic pressure sensors, includes a voltage integrator having an output, an integration capacitor and a resistor connected parallel to the integration capacitor. A current-to-voltage converter is connected upstream of the voltage integrator and has an input. A negative feedback branch has a series circuit of a farther voltage integrator and a voltage-to-current converter. The negative feedback branch is connected between the output of the voltage integrator and the input of the current-to-voltage converter.
    Type: Grant
    Filed: January 14, 1993
    Date of Patent: December 6, 1994
    Assignee: Siemens Aktiengesellschaft
    Inventor: Franz Wohlstreicher
  • Patent number: 5081410
    Abstract: A band-gap reference having a differential amplifier with first and second inputs and an output, and a voltage divider coupled to the differential amplifier output. A first transistor having a base, emitter and collector, has its base coupled to the voltage divider, the first transistor having an emitter current density of x. A second transistor having a base, emitter and collector, has its base coupled to the voltage divider, the second transistor having an emitter current density of nx, where n is fixed. A third transistor having a base, emitter and collector, has its base coupled to the emitter of the first transistor, and its collector coupled to the first input of the differential amplifier. A fourth transistor having a base, emitter and collector, has its base coupled to the emitter of the second transistor, and its collector coupled to the second input of the differential amplifier, and the emitter of the fourth transistor being coupled to the emitter of the third transistor.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: January 14, 1992
    Assignee: Harris Corporation
    Inventor: Grady M. Wood
  • Patent number: 4791381
    Abstract: An integrated amplifier circuit includes:first and second operational amplifiers each having a terminal connected to a supply potential node, and a terminal connected to a reference potential node;two ohmic voltage dividers each being formed of two resistors connected between an output of a respective one of the operational amplifiers and a first circuit node, and two further ohmic resistors each being connected between a respective tap of the voltage dividers and a respective inverting input of a respective one of the operational amplifiers, providing real negative feedback of the operational amplifiers;a third ohmic voltage divider formed of two resistors connected between a supply potential node and the first circuit node, an intermediate ohmic resistor connected between a tap of the third voltage divider and a second circuit node, and two ohmic supply resistors each being connected between the second circuit node and a respective non-inverting input of the operational amplifier; an ohmic series resistor c
    Type: Grant
    Filed: January 11, 1988
    Date of Patent: December 13, 1988
    Assignee: Siemens Aktiengesellschaft
    Inventor: Michael Lenz
  • Patent number: 4716378
    Abstract: An amplifier circuit for use, e.g., in audio appliances, comprises two amplifiers; a first amplifier for controlling the output voltage, and a second amplifier for driving output electric current. An impedance circuit is connected to both outputs of the first and second amplifiers. Thus, the amplifier circuit accurately controls output electric power in response to the input signal and yet providing sufficient electric current for driving a speaker.
    Type: Grant
    Filed: April 14, 1986
    Date of Patent: December 29, 1987
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideyasu Jiko, Tomoyuki Hayashi
  • Patent number: 4633189
    Abstract: An NF (Negative Feedback) tone control circuit in which a circuit gain of unity is maintained for a flat frequency response without the addition of active components. A voltage divider circuit which divides only an a.c. component of the output of an operational circuit is connected between the output of the operational amplifier circuit and a variable impedance circuit, the latter including the variable resistors of the tone control circuit.
    Type: Grant
    Filed: October 15, 1985
    Date of Patent: December 30, 1986
    Assignee: Pioneer Electronic Corporation
    Inventors: Yasuo Kawakami, Katsushi Kitamura
  • Patent number: 4543536
    Abstract: A charge amplifier includes an operational amplifier having first and second voltage dividers across its output connected to a capacitor and a resistor, respectively, in an R-C network returned to one input for magnifying the apparent value of the impedance of the capacitor and of the resistance of the resistor. Its output is also connected to an integrating network including another operational amplifier having its output supplied to a third voltage divider supplying signal to another input of the first operational amplifier. A pair of differentially coupled piezoelectric charge sources supply signal to the amplifier through filters and the second voltage divider has a portion shunted by a parallel connection of back-to-back diodes and another resistor for effectively attenuating response to low frequency signals.
    Type: Grant
    Filed: March 22, 1984
    Date of Patent: September 24, 1985
    Assignee: Fisher Controls International, Inc.
    Inventor: Richard H. Pederson
  • Patent number: 4502020
    Abstract: A wide-band direct-coupled transistor amplifier exhibits greatly improved settling time characteristics as the result of circuitry permitting the use of current feedback rather than voltage feedback in order to reduce the sensitivity of settling time and bandwidth to feedback elements without thereby affecting the manner in which feedback is applied externally by the user, reducing the sensitivity of settling time to the effects of temperature, eliminating saturation and turn-off problems within the amplifier that are related to bias control, to large input signals, and to high frequency input signals or those having fast rise times, and minimizing the sensitivity of settling time to power supply voltages.
    Type: Grant
    Filed: October 26, 1983
    Date of Patent: February 26, 1985
    Assignee: Comlinear Corporation
    Inventors: David A. Nelson, Kenneth R. Saller
  • Patent number: 4387345
    Abstract: A precision gain AC coupled operational amplifier circuit utilizing an integrated resistor voltage divider network and switched capacitors is provided. Precise gain is obtained by the use of integrated capacitors, and a low frequency stabilizing pole in the order of 10 Hertz is created by proper selection of the ratio of the resistors in the divider network.
    Type: Grant
    Filed: March 24, 1981
    Date of Patent: June 7, 1983
    Assignee: Motorola, Inc.
    Inventor: Stephen H. Kelley
  • Patent number: 4354163
    Abstract: A buffer amplifier is disclosed which has the ability to retain a high voltage from input to output and is capable of coupling to highly capacitive loads. The input impedance can be tailored up to several hundred thousand ohms. The frequency range is from 0.5 Hz to 6 KHz for highly capacitive loads. The amplifier comprises, in combination, an input impedance matching stage and a first and a second amplification stage. The input impedance matching stage consists solely of passive components. The first amplification stage comprises an operational amplifier in series with a high voltage transistor. Circuitry associated with the transistor provides separate controllable AC and DC gains. The AC gain is fed back through a feedback loop to the op amp and does not contribute much to the overall AC gain of the stage, which is determined by two resistors.
    Type: Grant
    Filed: April 30, 1980
    Date of Patent: October 12, 1982
    Assignee: Ford Aerospace & Communications Corporation
    Inventor: David S. Kato
  • Patent number: 4340865
    Abstract: An electric amplifier adapted to respond to an input signal of either polarity comprising a first differential amplifier OP1 which is arranged to drive through a load L a current whose value varies with the input but is independent of the load value and a second differential amplifier OP2 arranged to maintain the ratio of the amplifier output potentials relative to a datum potential at a predetermined value so that by appropriate choice of the datum potential and the predetermined ratio value the available output potential swing with a given supply voltage can be maximized.
    Type: Grant
    Filed: February 4, 1980
    Date of Patent: July 20, 1982
    Assignee: The General Electric Company Limited
    Inventor: Peter Woodhead
  • Patent number: 4322681
    Abstract: A device for analyzing and linearizing the frequency characteristics of electrical signals from unknown systems consists of identically constructed modules with variable transfer functions, which transfer functions are to be adjusted to a inverse component of the electrical signal to be analyzed. A procedure is disclosed in which the time constant and variable gain of each module is independently adjusted, whereby the variable gains and the time constants define the poles and the zeros of a polynomial, which polynomial describes the frequency characteristics of the unknown system.
    Type: Grant
    Filed: January 28, 1980
    Date of Patent: March 30, 1982
    Inventors: Alwin Luttmann, Andreas Plaas-Link, Klaus Muckenhoff
  • Patent number: 4268760
    Abstract: An amplitude limiting circuit is provided in which the input signal is fed to the non-inverting input terminal and the output is taken from the inverting input terminal of an operational amplifier having a feedback resistor connecting the inverting and output terminals of the amplifier. Either the input resistor, feedback resistor or operational amplifier supply voltages can be used to alter the upper and lower limit voltages of the circuit.
    Type: Grant
    Filed: March 7, 1979
    Date of Patent: May 19, 1981
    Assignee: Nippon Electric Co., Ltd.
    Inventors: Tadatsugu Tokunaga, Akira Fujii
  • Patent number: 4193040
    Abstract: The technical field to which this invention pertains is high-voltage amplifiers. The amplifier includes a high-voltage capacitor (C1) across which the output of the amplifier is developed. This capacitor is charged towards the supply potential (V) by a constant current generator (10). At the same time, the capacitor is continuously discharged by a controllable current generator (11). A voltage amplifier (13) connected to the input signal to be amplified and to a scaled-down version (R,R) of the output of the high-voltage amplifier, alters the rate at which the capacitor is discharged and, hence, the output voltage developed across the capacitor. The principal use of the invention is to drive the electrostatic deflection plates of an ion implantation machine or an electron beam milling apparatus. The invention may also be used to drive other highly capacitive loads, for example, piezo-electric crystal devices.
    Type: Grant
    Filed: November 2, 1978
    Date of Patent: March 11, 1980
    Assignee: Western Electric Company, Inc.
    Inventor: Barry Weissman
  • Patent number: 4156853
    Abstract: An active filter is disclosed for providing improved notch and band pass filters. The output to input frequency response of an active filter is mathematically expressed as a ratio of two polynominals in the Laplace operator S. In any notch filter, the coefficient of the S term in the numerator must be reduced to zero, while in any band pass arrangement the coefficient of the S term in the denominator is reduced to zero. The improved notch filter provides an input circuit for the operational amplifier portion of the filter which eliminates the S term in the numerator so that adjustments to reduce this term are unnecessary. Similarly, in the improved band pass filter, the S term in the denominator is eliminated in the feedback circuit provided for the operational amplifier, so that adjustment is unnecessary to eliminate the coefficient of S.
    Type: Grant
    Filed: February 9, 1978
    Date of Patent: May 29, 1979
    Assignee: Westinghouse Electric Corp.
    Inventor: Robert S. Peterson
  • Patent number: 4152659
    Abstract: A low noise differential amplifier circuit which requires only two operational amplifiers and which has lower noise than conventional differential amplifiers. An alternate embodiment is disclosed including circuitry for autozeroing the amplifier.
    Type: Grant
    Filed: September 23, 1977
    Date of Patent: May 1, 1979
    Assignee: Analogic Corporation
    Inventor: Bernard M. Gordon
  • Patent number: 4151478
    Abstract: A nonlinearly variable gain circuit is utilized to produce an inverted logarithmic S curve of gain versus potentiometer rotation while using a linear resistance taper potentiometer. An operational amplifier feedback circuit uses the linear potentiometer and a resistance network in combination.
    Type: Grant
    Filed: January 3, 1978
    Date of Patent: April 24, 1979
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Eric C. Heinrich, William H. Mosley, Jr.
  • Patent number: 4107618
    Abstract: The amplifier system comprises a pair of operational amplifiers with an appropriate resistance network such that when a reference voltage and differential signal are applied to the system, changes in the gain of the amplifier system will only change the gain of the differential signal and will not affect the reference voltage.
    Type: Grant
    Filed: August 4, 1977
    Date of Patent: August 15, 1978
    Inventor: Alfred Newman Ormond
  • Patent number: 4107622
    Abstract: A feedback resistor is interposed between a reversing input terminal of an audio amplifier and at least one impedance circuit. The impedance circuit is connected to an output terminal of the amplifier to receive an amplified audio signal from the amplifier. The signal controlled in its frequency characteristic in the impedance circuit. A fraction of the signal is negatively fed back to the amplifier through a feedback resistor.
    Type: Grant
    Filed: October 28, 1976
    Date of Patent: August 15, 1978
    Assignee: Victor Company of Japan, Limited
    Inventor: Kazuya Toyomaki
  • Patent number: 4099134
    Abstract: An amplifier whose transmission factor is to be controlled as a function of a control voltage and including an amplifier member having a negating input, connected to have its impedance varied by the control voltage and an electronically controllable variable impedance having one side connected to the amplifier member output, a second impedance connected between the other side of the first impedance and ground, and a switch assembly for switching the connections within the amplifier between two operating states providing mutually complementary control characteristics, the amplifier member output providing the amplifier output in one operating state and being connected to the negating input in the other operating state, and the point of connection between the impedances being connected to the negating input in the one operating state and providing the amplifier output in the other operating state.
    Type: Grant
    Filed: June 21, 1977
    Date of Patent: July 4, 1978
    Assignee: Licentia Patent-Verwaltungs-G.m.b.H.
    Inventor: Ernst Schroder
  • Patent number: 4091333
    Abstract: A transconductance amplifier circuit including two operational amplifiers, as shown in the accompanying drawing, is disclosed. The gain of the amplifier circuit is determined by the resistances R1, R2, R3 and R4. The scale factor relating the output current i.sub.out to the input voltage e.sub.in is determined by the setting of the switches S1, S2, and S3, which adjust the amount of resistance between the output current terminal I.sub.o and the output terminal of the second operational amplifier A2. For R1/R2 = 1; R3/R4 = 1; and switch S1 closed i.sub.out = e.sub.in /R5. This transconductance amplifier circuit provides common mode rejection between the input voltage and the output current.
    Type: Grant
    Filed: July 25, 1977
    Date of Patent: May 23, 1978
    Assignee: Valhalla Scientific Incorporated
    Inventor: Guy Carlyle Thrap
  • Patent number: 4087758
    Abstract: A reference voltage source circuit includes two transistors having their collectors connected to the input terminals of a differential amplifier. The transistor terminals are connected in common, and to the output of the amplifier.In accordance with one aspect of the present invention, variable resistance structure is employed to control the collector currents in the transistor to maintain the temperature-output voltage transfer characteristic at a low level. In accordance with another aspect of the present invention, the transistor supply may depend from the amplifier output to reduce the influence of supply voltage variations on the regulated output potential.
    Type: Grant
    Filed: July 20, 1976
    Date of Patent: May 2, 1978
    Assignee: Nippon Electric Co., Ltd.
    Inventor: Kyuichi Hareyama
  • Patent number: 4079331
    Abstract: A condition responsive element, disclosed as a negative temperature coefficient thermistor, operates in conjunction with a bridge circuit to provide a differential input to a special direct current amplifier system. The amplifier system utilizes a combination of positive feedback and negative feedback with the negative feedback always exceeding the level of the positive feedback under steady state operating conditions. The output of the amplifier means further is connected to the lowest energizing potential for the amplifier means through a network that includes a relatively fixed voltage dropping means so that changes in the negative feedback can be made to change the gain of the amplifier system with a minimum of offset or change in calibration of the condition responsive device.
    Type: Grant
    Filed: February 9, 1977
    Date of Patent: March 14, 1978
    Assignee: Honeywell Inc.
    Inventors: B. Hubert Pinckaers, Robert T. Ruminsky
  • Patent number: 4078215
    Abstract: An electronic filter circuit having controlled "Q" with variations in attenuation. A plurality of filter networks are connected in parallel between the output and the input of an amplifier in a manner such as to be capable of selectively providing negative feedback to the amplifier. Each filter network includes inductive, capacitive and resistive elements, with a potentiometer forming part of the resistance thereof. Each potentiometer is connected in series with a resistor having the same value thereas, the arm of the potentiometer being connected to its associated filter network such that the "cut" to which the potentiometer is set determines the total value of the resistance presented by the filter network in the feedback circuit. The potentiometers and associated resistors are each connected in series with each other, these series connected elements being connected in parallel between the input and the output of a unity gain amplifier.
    Type: Grant
    Filed: November 26, 1976
    Date of Patent: March 7, 1978
    Assignee: Altec Corporation
    Inventor: Billy Herman Vinson
  • Patent number: 4055813
    Abstract: A single adjustable control is commonly connected with each of a plurality of feedback channels, which are selectively coupled in an amplifier circuit to provide the latter with different basic gains, to adjust the respective basic gains of the amplifier circuit by corresponding fractional or proportional amounts of respective ranges of permissible gain chain for each channel, thereby simultaneously to correct or to calibrate each channel for different amounts of drift of the like.
    Type: Grant
    Filed: June 16, 1976
    Date of Patent: October 25, 1977
    Assignee: Sterndent Corporation
    Inventor: Park French
  • Patent number: 4037170
    Abstract: A difference amplifier, the construction of which includes operational amplifier, has an extended amplitude range of common mode signal. The input of the circuit which is applied to the inversion input of the operating amplifier is applied to the latter through an attenuation network. An adjustment of the other resistor values in the circuit is made to appropriately retain the desirable characteristics of keeping common mode rejection.
    Type: Grant
    Filed: April 5, 1976
    Date of Patent: July 19, 1977
    Assignee: Stromberg-Carlson Corporation
    Inventor: Glenn L. Richards
  • Patent number: 3983504
    Abstract: An improved filtering circuit connected to the inverting terminal of an operational amplifier having connected in parallel a first resistor and three series capacitors. Two series resistors are connected in parallel with the center capacitor and the junction between the two series resistor is connected to a fixed potential.
    Type: Grant
    Filed: November 21, 1975
    Date of Patent: September 28, 1976
    Inventor: Franklin Moy
  • Patent number: 3980942
    Abstract: An arrangement for electrically heating a semiconductor rod which is simultaneously growing by means of materials deposited from a gas phase, wherein the heating current circuit is formed by a heating current source and an electronic switch which is controllable by a variable auxiliary voltage. The heating current is applied to a smoothing circuit by way of a rectifier circuit which is coupled with the heating current circuit. The initial voltage of the smoothing circuit is compared with a desired voltage and the difference voltage determined by this comparison serves to control the generator which supplies the auxiliary voltage. The smoothing circuit is coupled with a preamplifier whose output is connected with the movable tap of a potentiometer. A fixed terminal of the potentiometer is connected to a source which supplies the desired voltage and to the input of a subsequent control amplifier. Another fixed contact of the potentiometer is connected in a feedback circuit to the input of the preamplifier.
    Type: Grant
    Filed: October 24, 1972
    Date of Patent: September 14, 1976
    Assignee: Siemens Aktiengesellschaft
    Inventor: Hans Stut
  • Patent number: 3972006
    Abstract: 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: Grant
    Filed: September 20, 1974
    Date of Patent: July 27, 1976
    Assignee: Beckman Instruments, Inc.
    Inventor: Frank A. Ruegg
  • Patent number: 3939433
    Abstract: A feedback circuit for feeding back the output voltage of a comparing amplifier to the input circuit of the comparing amplifier for causing a steep change in the output voltage so as to stabilize the operation of the succeeding circuit. The feedback circuit includes means for applying the feedback voltage to a low potential portion of the input circuit of the comparing amplifier.
    Type: Grant
    Filed: February 12, 1974
    Date of Patent: February 17, 1976
    Assignee: Hitachi, Ltd.
    Inventors: Tomoyuki Okada, Seiji Suda