Including A Push-pull Stage Patents (Class 330/118)
  • Patent number: 10218320
    Abstract: The present invention provides a vacuum tube audio amplifier which includes an audio pre-amplifying portion and an audio output transforming portion. The audio pre-amplifying portion includes an equalizer for enhanced sound quality and amplifies an audio signal, which is subsequently transmitted to the audio output transforming portion. Furthermore, the audio output transforming portion includes an audio output transformer which includes a plurality of stacked E-shaped silicon steel sheets and a plurality of stacked I-shaped silicon steel sheets, wherein the stacked E-shaped silicon steel sheets and the stacked I-shaped silicon steel sheets have a same height which is smaller than or equal to 48 mm.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: February 26, 2019
    Assignee: ECHOWELL ELECTRONICS CO., LTD.
    Inventor: Hsi-Hsien Chen
  • Patent number: 9668050
    Abstract: Provided is an impedance conversion circuit of a condenser microphone which includes a first electron tube operated in grounded-cathode mode to whose grid an output signal from a condenser microphone unit is inputted, and from whose plate a signal is outputted, a first emitter-follower circuit configured to receive a signal based on a plate output of the first electron tube and amplify a current, and a first feedback element configured to transmit a feedback signal from an emitter of a transistor configuring the first emitter-follower circuit to the grid of the first electron tube. And the impedance conversion circuit can achieve a wide dynamic range while using a voltage amplifier circuit with an electron tube at an initial stage.
    Type: Grant
    Filed: August 5, 2016
    Date of Patent: May 30, 2017
    Assignee: KABUSHIKI KAISHA AUDIO-TECHNICA
    Inventor: Hiroshi Akino
  • Patent number: 9590570
    Abstract: To provide an impedance converter circuit for a condenser microphone which can secure a wide dynamic range using a voltage amplifier circuit. The impedance converter circuit is provided with: a first electron tube of a cathode grounded type in which an output signal of a condenser microphone unit is input into a grid and output from a plate; a second electron tube in which an output signal from the plate of the first electron tube is input into a grid and output from at least a cathode; and a feedback element configured to transmit a feedback signal from the cathode of the second electron tube to the grid of the first electron tube.
    Type: Grant
    Filed: November 19, 2015
    Date of Patent: March 7, 2017
    Assignee: KABUSHIKI KAISHA AUDIO-TECHNICA
    Inventor: Hiroshi Akino
  • Patent number: 9537447
    Abstract: In accordance with an embodiment, a voltage controlled oscillator (VCO) includes a VCO core having a plurality of transistors, a bias resistor coupled between collector terminals of the VCO core and a first supply node, and a varactor circuit coupled to emitter terminals of the VCO core. The bias resistor is configured to limit a self-bias condition of the VCO core.
    Type: Grant
    Filed: July 24, 2015
    Date of Patent: January 3, 2017
    Assignee: Infineon Technologies AG
    Inventor: Saverio Trotta
  • Patent number: 9343954
    Abstract: The application discloses a multi-input DC converter and a PFC circuit. The multi-input DC converter of the application includes n diodes, a transformer, a switching transistor, a rectifier and filter circuit, and a load. The transformer includes a primary winding and a secondary winding, the number of turns of the primary winding is N1, and the primary winding is divided into n sections by leading out n?1 taps in a specific manner; anodes of the n diodes are respectively connected to n input sources in turn, cathodes of the n diodes are respectively connected to a first terminal of the primary winding and n?1 tap terminals in turn, a second terminal of the primary winding is grounded through the switching transistor, and the secondary winding delivers energy to the rectifier and filter circuit and then to the load. The structure is simple, and the cost is low.
    Type: Grant
    Filed: February 29, 2012
    Date of Patent: May 17, 2016
    Assignee: SHENZHEN VAPEL POWER SUPPLY TECH. CO., LTD.
    Inventors: Zhanwei Li, Lixiang Liu
  • Patent number: 8446228
    Abstract: An oscillator circuit comprises a push-push oscillator and a differential output, comprising a first and a second output circuit. The push-push oscillator has a first and a second branch. Each of the first and second branch comprises an own voltage divider branch of a common bridge circuit. Each of the first and second voltage divider branches comprises an own pair of micro-strip lines connected in series. Each of the first and second voltage divider branches has an own tap. Both taps are connected to each other by at least one of a first capacity and a micro-strip line. The differential output comprises a first and a second output terminal. The first output terminal is connected via the first output circuit to a first node. The second output terminal is connected via the second output circuit to a second node. Each of the first and second nodes of the push-push oscillator is a common node of both of the first and the second branches.
    Type: Grant
    Filed: January 5, 2009
    Date of Patent: May 21, 2013
    Assignee: Freescale Semiconductor, Inc.
    Inventor: Saverio Trotta
  • Publication number: 20120188010
    Abstract: A power amplifier includes an amplifying circuit, and first through third transmission lines. The amplifying circuit amplifies an input signal having a fundamental frequency to generate a first amplified signal and a second amplified signal whose phase is opposed to the first amplified signal. The first transmission line adds a first group of phases, different in correspondence with a frequency, to the first amplified signal by using a left-handed material to generate a first transmission signal. The second transmission line adds a second group of phases, different in correspondence with a frequency, to the second amplified signal by using a right-handed material to generate a second transmission signal. The third transmission line overlaps the first and the second transmission signals to generate an output signal. The first and the second group of phases include a phase difference configured to weaken a second harmonic and a third harmonic.
    Type: Application
    Filed: February 3, 2010
    Publication date: July 26, 2012
    Applicant: NEC CORPORATION
    Inventor: Akio Wakejima
  • Patent number: 8022776
    Abstract: The present disclosure relates to coupled circuits and methods of coupling circuits having a power supply wherein a plurality of transistors are inductively coupled directly to the power supply for providing a single DC supply voltage directly to each of the plurality of transistors, and wherein a plurality of transformers have primary and secondary windings, the primary and secondary windings providing, at least in part, inductive loads for inductively coupling the plurality of transistors to the power supply, the plurality of transformers also providing an AC signal path for coupling neighboring ones of the plurality of transistors together.
    Type: Grant
    Filed: August 2, 2006
    Date of Patent: September 20, 2011
    Assignee: The Regents of the University of California
    Inventors: Mau-Chung Frank Chang, Daquan Huang, Tim Richard LaRocca
  • Patent number: 7567784
    Abstract: A tuner, a broadcast signal processing apparatus and method, which satisfy reception sensitivity of both terrestrial and cable televisions, when selecting a broadcast signal through a single conversion tuner, are provided. A tuner selects a broadcast signal of a selected channel. The tuner includes an input filter that filters a received broadcast signal into plural frequency bands based on a predetermined frequency band. An amplifier amplifies a second signal having an original phase induced by an output signal of the respective frequency bands, and a first signal having an opposite phase of the second signal, and outputs the signal induced by the amplified first and second signals as an amplification signal of the signal in the respective frequency bands. An inter-stage filter filters a frequency of the broadcast signal corresponding to the selected channel among the amplification signals output from the amplifier.
    Type: Grant
    Filed: May 24, 2006
    Date of Patent: July 28, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Yong-ho Choi
  • Patent number: 7193458
    Abstract: A power supply for a guitar amplifier and the guitar amplifier and method of operating the guitar amplifier. The power supply includes an alternating current power input having a secondary winding and a filament winding, an output and a first vacuum tube rectifier coupled between the secondary winding of the power input and the output for rectifying the alternating current at the power input. At least a second rectifier is provided which is selectively couplable in parallel with the first vacuum tube rectifier. The at least one second rectifier can be a vacuum tube rectifier with each of the first and second rectifiers having a cathode continually energized by the filament winding, a solid state rectifier or both. The output amplifier has an output transformer having a primary winding with a center tap and with a first pair of vacuum tube amplifiers having their cathodes being coupled together and their plates coupled to the primary winding on opposite sides of the center tap.
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: March 20, 2007
    Inventor: Randall C. Smith
  • Patent number: 6937093
    Abstract: An amplifier is described including a pair of cathode-coupled pentode vacuum tubes. A first pentode of the pair includes a control grid configured to receive an input signal. A second pentode of the pair includes a control grid configured to be coupled to an input reference signal. A cascaded voltage regulator includes a first stage configured to generate a plate reference voltage for providing voltage to a plate of each pentode. The regulator includes a second stage configured to generate a screen reference voltage based on the plate reference voltage for providing voltage to a screen grid of each pentode. The amplifier can also include a push-pull output stage having a servo circuit configured to adjust the control bias signal for one of a pair of vacuum tubes included in the stage until the plate currents in the pair of tubes are substantially equal.
    Type: Grant
    Filed: January 7, 2004
    Date of Patent: August 30, 2005
    Assignee: Bretza, Ltd.
    Inventor: Terence D. Tekushan
  • Patent number: 6621335
    Abstract: A Class D amplifier device with reduced power consumption uses a passive RC network. The output of the RC network directly feeds a comparator resulting in increased efficiency. The RC network is configured to perform several functions, including the low pass filtering of the feedback signal to remove high frequency/high amplitude clock components and provides a DC path from its output to reduce duty cycle errors. Additionally, the input signal receives low pass filtering, creating a generally flat frequency response. Finally, the clock signal is filtered to generate a triangle wave of good linearity and appropriate amplitude.
    Type: Grant
    Filed: February 22, 2002
    Date of Patent: September 16, 2003
    Assignee: Microsemi Corporation
    Inventor: Bengt-Olov Andersson
  • Publication number: 20030169106
    Abstract: A power supply for a guitar amplifier and the guitar amplifier and method of operating the guitar amplifier. The power supply includes an alternating current power input having a secondary winding and a filament winding, an output and a first vacuum tube rectifier coupled between the secondary winding of the power input and the output for rectifying the alternating current at the power input. At least a second rectifier is provided which is selectively couplable in parallel with the first vacuum tube rectifier. The at least one second rectifier can be a vacuum tube rectifier with each of the first and second rectifiers having a cathode continually energized by the filament winding, a solid state rectifier or both. The output amplifier has an output transformer having a primary winding with a center tap and with a first pair of vacuum tube amplifiers having their cathodes being coupled together and their plates coupled to the primary winding on opposite sides of the center tap.
    Type: Application
    Filed: March 3, 2003
    Publication date: September 11, 2003
    Inventor: Randall C. Smith
  • Publication number: 20030090320
    Abstract: A fiber-to-the-home (FTTH) system transmits forward and reverse optical signals, such as video, voice, and data signals, via optical fiber, and includes a plurality of home network units. The home network units include an FTTH optical receiver for receiving at least one of the video, voice, and data signals. A triplexer distinguishes and separates the video, voice, and data signals, wherein the video signals have a first wavelength and the voice and data signals have a second wavelength. The voice and data signals are provided to the home network unit for further processing. The triplexer provides an electrical signal to the amplifier stages. The amplifier stages include a preamplifier stage and a postamplifier stage. A gain control circuit automatically adjusts the gain of the video signal based upon the input power level to the FTTH optical receiver. Additionally, a tilt network performs level compensation for externally located coaxial cable.
    Type: Application
    Filed: November 14, 2001
    Publication date: May 15, 2003
    Inventors: John Skrobko, Robert R. Riggsby
  • Patent number: 6140870
    Abstract: A hybrid thermionic valve and solid state audio amplifier. A complete tube amplifier is scaled to produce a relatively low power yet also retain its small and large signal distortion characteristics. The output of the scaled amplifier is amplified by a relatively linear solid state amplifier. In one embodiment of the invention, a plurality of tube amplifiers are coupled in parallel and input to a mixing circuit for selectably mixing the outputs of the tube amplifiers and providing the mixed outputs to the solid state amplifier.
    Type: Grant
    Filed: May 18, 1998
    Date of Patent: October 31, 2000
    Inventor: Erick M. Cook
  • Patent number: 5912585
    Abstract: In a direct coupled type vacuum tube amplifying circuit, to stabilize the operation and simplify the feedback loop, a plate power source EB5 is connected to a plate of a vacuum tube V5 of a first stage through a constant current source 1. A grid of a vacuum tube V6 of a next stage is connected to the plate of the vacuum tube V5 through a first resistance R3. A second resistance R4 is connected between the grid and the cathode of the vacuum tube V6. A negative power source EC6 is connected to the resistance R4 through a constant current source 2. In this constitution, the grid bias voltage of the second vacuum tube V6 is defined by the voltage drop of the second resistance R4.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: June 15, 1999
    Assignee: Zanden Audio System Co., Ltd.
    Inventor: Kazutoshi Yamada
  • Patent number: 5872512
    Abstract: An apparatus and method for reducing errors in a battery powered sensing circuit uses two pull-up resistors. The first resistor has a value selected to minimize battery drain and the second resistor has a value selected to reduce dendrite or other parasitic parallel resistance. The resistors are selectively connected to the circuit based on a predetermined sequence and/or time interval.
    Type: Grant
    Filed: February 9, 1996
    Date of Patent: February 16, 1999
    Assignee: Interactive Technologies, Inc.
    Inventors: Gerald M. Kackman, Robert E. Brunius
  • Patent number: 5793252
    Abstract: An electronic amplifying apparatus for sound reproduction and musical instrument amplification including at least two pairs of power output devices which are independently switchable between triode and pentode operation. The amplifier further contains a switch apparatus to select the amount of negative feedback within the amplifier.
    Type: Grant
    Filed: December 9, 1996
    Date of Patent: August 11, 1998
    Assignee: Mesa Boogie, Limited
    Inventor: Randall C. Smith
  • Patent number: 5668499
    Abstract: A power amplifier has a distortion control circuit responsive to a clipping detector for loading said amplifier input with a signal sufficient to reduce the input to the tube grids to a level below clipping.
    Type: Grant
    Filed: January 16, 1996
    Date of Patent: September 16, 1997
    Assignee: Peavey Electronics Corporation
    Inventors: James Robert Albert, Jack C. Sondermeyer
  • Patent number: 5572099
    Abstract: A phase-locked loop (or frequency-locked loop) based circuit for controlling the drive applied to a DC polyphase motor is disclosed. The disclosed circuit includes a clamp circuit, connected to the input of the motor drive amplifier, for limiting the current applied to the drive amplifier, in order to ensure that the power supply is not overloaded. According to one embodiment of the invention, the clamp circuit includes a buffer amplifier having a source leg and a sink leg. During a current control mode, both the source leg and sink leg of the buffer amplifier are enabled to drive the input of the motor drive amplifier; the buffer amplifier is a differential amplifier and applies a feedback signal from the drive amplifier input to control the current applied thereto according to an input limit signal.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: November 5, 1996
    Assignee: SGS-Thomson Microelectronics, Inc.
    Inventor: Francesco Carobolante
  • Patent number: 5498996
    Abstract: A high-power, high-fidelity tube amplifier which includes a plurality of output tubes connected in parallel with individual current sinks and a plurality of parasitic suppression components. Each current sink is electrically coupled to its corresponding output tube such that the output impedance of the current sink decreases as the grid current of the corresponding output tube increases.
    Type: Grant
    Filed: November 21, 1994
    Date of Patent: March 12, 1996
    Assignee: Wavestream Kinetics
    Inventor: Scott G. Frankland
  • Patent number: 5363056
    Abstract: An electronic circuit provides a linear output from an amplifying device, such as a hybrid push-pull amplifier, which has inherent distortion. In a preferred embodiment, the distortion of the hybrid amplifier is compensated by nesting a pair of hybrid push-pull amplifiers within a push-pull circuit configuration. In another embodiment, the distortion of the hybrid amplifier is compensated by providing a predistorted signal equal in magnitude, but opposite in sign, to the distortion introduced by the nonlinear device. The input signal is split into two electrical paths with the primary part of the signal applied directly to the hybrid amplifier, with a time delay to compensate for delay in the secondary path. Elements within the secondary path generate both even and odd order distortion products. These are recombined with the primary signal in proper phase and amplitude, and the resulting signal is applied to the hybrid amplifier for canceling distortion in the hybrid amplifier.
    Type: Grant
    Filed: April 27, 1993
    Date of Patent: November 8, 1994
    Assignee: Ortel Corporation
    Inventor: Henry A. Blauvelt
  • Patent number: 5302912
    Abstract: A high-performance, distortion-free, audio push-pull amplifier has a class A driver stage that drives a class B push-pull output stage that is coupled to a load through a transformer that has a center tap primary with screen taps. The driver tube cathodes are coupled to the output tube grids. The driver tube plates are tied to the screen taps on the output transformer primary. These taps are also coupled to the output tube screen grids. At low power levels the driver stage drives the load through the output transformer. As power level rises the power stage supplies more and more of the output power. This circuit avoids notch or crossover distortion at low power levels.
    Type: Grant
    Filed: May 10, 1993
    Date of Patent: April 12, 1994
    Inventor: Alan M. Grant
  • Patent number: 4918394
    Abstract: The present invention is an audio frequency power amplifier input circuit having improved vacuum tube circuit topology. The improved circuit includes a direct current feedback circuit within the input circuitry which stabilizes the operating point of a phase inverter. The feedback circuit maintains optimum operation of the circuit despite variations in tube characteristics or supply voltages. Another aspect of the improved circuit comprises a low impedance phase inverter which improves the drive capability of the phase inverter to push-pull power output vacuum-tube grids.
    Type: Grant
    Filed: March 23, 1989
    Date of Patent: April 17, 1990
    Assignee: Modafferi Acoustical Systems, Ltd.
    Inventor: Richard Modafferi
  • Patent number: 4797628
    Abstract: The present invention provides a modified distributed amplifier which is capable of providing push-pull operation without the loading losses of conventional push-pull combining. The modified distributed amplifier comprises a distributed amplifier configuration and with signal inverting means, such as a wide bandwidth transmission line transformer, interconnected into both the input and output lines. The signal inverting means are most effectively placed at the electrical centers of the lines, but may be placed at any positions in the individual lines to produce optimum performance to specific applications. The separate segments of the distributed amplifier separated by the signal inverting means operate in opposed phase but the signals output to the load add in phase thus providing push-pull operation.
    Type: Grant
    Filed: March 23, 1988
    Date of Patent: January 10, 1989
    Inventors: Michael E. Gruchalla, David C. Koller
  • Patent number: 4751472
    Abstract: The invention relates to a high frequency amplifier for coupling a load with a tetrode which is used as the amplifier tube and which is provided with a regulating circuit with a set point adjuster for the anode voltage. The regulating circuit can also be influenced by a control variable as the set point feedforward which is dependent on the tetrode screen grid current and which is used for automatically matching the anode voltage to the operating conditions of the load. For the power dissipation of the screen grid and anode of the tetrode, a regulating circuit can be provided with a limitation of the controlling high frequency power dependent on the screen grid current.
    Type: Grant
    Filed: October 29, 1986
    Date of Patent: June 14, 1988
    Assignee: Herfurth GmbH
    Inventors: Karl H. Knobbe, Hellmut Noldge
  • Patent number: 4713624
    Abstract: A vacuum tube amplifying apparatus provides predetermined varying dynamic response characteristics in order to enhance the playing characteristics of musical instruments, especially guitar.
    Type: Grant
    Filed: October 7, 1986
    Date of Patent: December 15, 1987
    Inventor: Randall C. Smith
  • Patent number: 4644289
    Abstract: A variable power amplifier having a constant current differential amplifier driving a cascaded driving amplifier, a variable power amplifier including a vacuum tube for selectively amplifying output signals wherein the drive of the variable power amplifier is determined by the plate shunt resistive loading of the vacuum tube, a push-pull amplifier including an output transformer operatively coupled to the variable power amplifier and to an amplifier output terminal to amplify and apply to the amplifier output terminal a selectively amplified output signal, and a variable damping circuit including a sensing element for sensing the loading on the output tranformer and a circuit for defining a feedback loop for producing a feedback signal having magnitude and polarity which are determined by the sensing element and wherein the variable damping circuit includes a circuit for applying the feedback signal as an input to the constant current differential amplifier to control the current level thereof as a function o
    Type: Grant
    Filed: December 3, 1984
    Date of Patent: February 17, 1987
    Assignee: Carter-Duncan Corporation
    Inventors: Bruce L. Kennedy, Joseph K. Beller, Roger A. Modjeski
  • Patent number: 4455536
    Abstract: A push-pull microwave amplifier in which an input signal is split into two ransmission paths in a manner which simulates the behavior of a center-tapped transformer over a broad frequency range. The input signal is first divided into two identical paths and then passed down first and second transmission line segments in the two paths bi-directionally. One of the transmission line segments is terminated in an open circuit and the other in a short circuit so that the reflected signals have the opposite polarities. By making the transmission line segments of equal length, the opposite polarity signals emerge from the transmission line segments at the same time. The signals are then amplified and then passed again bi-directionally along third and fourth transmission line segments terminated in short and open circuits so as to re-convert the signals to the same polarity. The signals are then summed to produce the composite amplified output signal.
    Type: Grant
    Filed: January 21, 1982
    Date of Patent: June 19, 1984
    Assignee: International Telecommunications Satellite Organization (INTELSAT)
    Inventor: Ronald E. Stegens
  • Patent number: 4337439
    Abstract: A distributed amplifier is provided with an output filter line with the output terminals of a plurality of individual amplifying devices connected to different points along the output filter line. Instead of dimensioning the impedance of the output filter line to provide a perfectly uniform frequency response, it is arranged as a wide band multiple quarter wave impedance transformer. The use of this kind of output filter line provides superior performance when the amplifier is used with mismatched loads and the frequency response can still be very good.
    Type: Grant
    Filed: October 24, 1979
    Date of Patent: June 29, 1982
    Assignee: The Marconi Company Limited
    Inventor: Boleslaw M. Sosin
  • Patent number: 4153882
    Abstract: This invention provides a method and means for amplifying signal waves with high efficiency that comprises signal sampling means operating at the Nyquist rate or greater, sample-quantizing means, a plurality of circuits that link the quantizing means to a plurality of controlled current-switching means, combining means that combines the outputs of the plurality of switching means, and filter means that reconstructs an amplified facsimile of the signal.
    Type: Grant
    Filed: March 24, 1978
    Date of Patent: May 8, 1979
    Inventors: Charles B. Fisher, Sidney T. Fisher
  • Patent number: 4047120
    Abstract: A protective coupling circuit is located between the D.C. supply voltage the amplifier components of a push-pull switching amplifier to suppress transients created during switching. The coupling circuit comprises a power supply filter with an inductor coil and capacitor, and circuitry for limiting the voltage on the individual switching elements and the output coil. Excess voltages caused by transients are fed to the power supply filter. In an alternative embodiment the power supply filter inductor coil is actually an auxiliary winding on the amplifier output transformer rather than a separate coil. This allows for use of some smaller capacity circuit elements.
    Type: Grant
    Filed: July 15, 1976
    Date of Patent: September 6, 1977
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Harold Wilbur Lord, Jimmy Dale Rogers
  • Patent number: 4028633
    Abstract: A drive circuit responsive to the phase of the amplifier output current eres that the non-conducting amplifier element remains off while the other amplifier element conducts. The output current phase can be detected either from the individual amplifier element outputs or from their combined outputs. Adjustments are made to compensate for any phase shift which occurs between the input to the amplifier and the point in the output at which the phase is detected.
    Type: Grant
    Filed: July 19, 1976
    Date of Patent: June 7, 1977
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Jimmy Dale Rogers, Michael Earl Creecy