Power Or Bias Supply Circuits And Control Thereof Patents (Class 330/123)
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Patent number: 11042140Abstract: A power supply control system includes a power generator for providing a signal to a load. The power generator includes a power controller controlling a power amplifier. The power generator includes an adaptive controller for varying the output signal controlling the power amplifier. The adaptive controller compares an error between a measured output and a predicted output to determine adaptive values applied to the power controller. The power generator also includes a sensor that generates an output signal that is digitized and processed. The sensor signal is mixed with a constant K. The constant K is varied to vary the processing of the sensor output signal. The value K may be commutated based on the phase, frequency, or both phase and frequency, and the bandwidth of K is determined by coupled power in the sensor output signal.Type: GrantFiled: March 11, 2019Date of Patent: June 22, 2021Assignee: MKS Instruments, Inc.Inventors: David J. Coumou, Yuriy Elner, Aung Toe, Daniel M. Gill, Eldridge M. Mount, IV, Shaun Smith
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Patent number: 11009843Abstract: A power supply control system includes a power generator for providing a signal to a load. The power generator includes a power controller controlling a power amplifier. The power generator includes an adaptive controller for varying the output signal controlling the power amplifier. The adaptive controller compares an error between a measured output and a predicted output to determine adaptive values applied to the power controller. The power generator also includes a sensor that generates an output signal that is digitized and processed. The sensor signal is mixed with a constant K. The constant K is varied to vary the processing of the sensor output signal. The value K may be commutated based on the phase, frequency, or both phase and frequency, and the bandwidth of K is determined by coupled power in the sensor output signal.Type: GrantFiled: March 11, 2019Date of Patent: May 18, 2021Assignee: MKS Instruments, Inc.Inventors: David J. Coumou, Yuriy Elner, Aung Toe, Daniel M. Gill, Eldridge M. Mount, IV, Shaun Smith
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Patent number: 10026375Abstract: An output amplifier of a source driver and a control method thereof are provided. The output amplifier includes a first switch circuit, a second switch circuit, a third switch circuit, a first input stage circuit, a second input stage circuit, a first active load circuit, a second active load circuit, a first positive output stage circuit, a first negative output stage circuit, a second positive output stage circuit and a second negative output stage circuit. In a first display stage of the control method, the first switch circuit outputs a positive reference signal through a first output terminal and outputs a negative reference signal through a second output terminal. In a second display stage of the control method, the signals outputted by the first output terminal and the second output terminal are exchanged.Type: GrantFiled: November 21, 2016Date of Patent: July 17, 2018Assignee: HIMAX TECHNOLOGIES LIMITEDInventors: Jia-Hui Wang, Chuan-Chien Hsu, Hung-Yu Huang
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Patent number: 10013936Abstract: The present invention relates to a technology for outputting a gamma voltage in a source driver of a display device. A gamma voltage generation circuit of a source driver in accordance with the present invention may form wide high and low gamma voltage ranges even when a negative power supply voltage and a positive power supply voltage are asymmetrical to each other.Type: GrantFiled: October 23, 2014Date of Patent: July 3, 2018Assignee: SILICON WORKS CO., LTDInventors: Yong Sung Ahn, Jung Min Choi
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Patent number: 9728378Abstract: In one embodiment, an RF generator includes an RF amplifier comprising an RF input, a DC input, and an RF output, the RF amplifier configured to receive at the RF input an RF signal from an RF source; receive at the DC input a DC voltage from a DC source; and provide an output power at the RF output; and a control unit operably coupled to the DC source and the RF source, the control unit configured to receive a power setpoint indicative of a desired output power at the RF output; determine a power dissipation at the RF generator; alter the DC voltage to decrease the power dissipation at the RF generator; and alter the RF signal to enable the output power at the RF output to be substantially equal to the power setpoint.Type: GrantFiled: July 29, 2016Date of Patent: August 8, 2017Inventors: Imran Ahmed Bhutta, Tomislav Lozic
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Patent number: 9666143Abstract: An amplifying circuit includes a first differential amplifier (first differential pair) and a second differential amplifier (second differential pair) having an input capacitance smaller than the first differential amplifier. The amplifying circuit switches between the first differential amplifier (first differential pair) and the second differential amplifier (second differential pair) in response to an amplification mode setting signal to perform amplification processing of an input signal.Type: GrantFiled: September 15, 2015Date of Patent: May 30, 2017Assignee: LAPIS SEMICONDUCTOR CO., LTD.Inventors: Hiroyoshi Ichikura, Koji Higuchi
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Patent number: 8788898Abstract: An apparatus is provided that comprises a test circuit; a first receiver unit arranged to receive test commands and to provide the test commands to the test circuit; a power supply unit arranged to supply power to the test circuit and to the first receiver unit; a second receiver unit arranged to receive power commands. The second receiver is arranged to control the operation of the power supply unit in response to the power commands received by the second receiver unit.Type: GrantFiled: June 3, 2011Date of Patent: July 22, 2014Assignee: STMicroelectronics (Research & Development) LimitedInventor: Edward Kent
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Patent number: 8654867Abstract: A method for generating an amplified radio frequency (RF) signal is provided. In-phase (I) and quadrature (Q) signals are received and interleaved so as to generate a time-interleaved signal. Delayed time-interleaved signals are then generated from the time interleaved signal, and each of the delayed time-interleaved signals is amplified so as to generate a plurality of amplified signals. The amplified signals are then combined with a transformer, where the delayed time-interleaved signals are arranged to generate a filter response with the transformer.Type: GrantFiled: December 7, 2011Date of Patent: February 18, 2014Assignee: Texas Instruments IncorporatedInventors: Rahmi Hezar, Lei Ding, Joonhoi Hur, Baher S. Haroun
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Patent number: 8575975Abstract: A system and method for charging heavy capacitive loads may comprise an n-stage stacked charging circuit wherein n is an integer greater than one which may comprise n?1 capacitors and a voltage supply, each sequentially electrically connected to the capacitive load in an order through a respective first through nth switch during a respective first through nth charging time period; the n?1th capacitors each sequentially electrically connected to the capacitive load in reverse order during a first through n?1th discharging time period through the respective n?1th through first switches. The system and method may comprise an n+1th switch electrically connecting the capacitive load to ground during an nth discharging period. The capacitive load may comprise a piezoelectric element, which may comprise an inkjet printer head inkjet actuator.Type: GrantFiled: September 30, 2009Date of Patent: November 5, 2013Assignee: Cirrus Logic, Inc.Inventors: Anindya Bhattacharya, John Melanson
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Patent number: 8541733Abstract: The invention provides a laser light detection circuit that prevents a peak output occurring when the circuit switches between the operation stop mode and the operation mode so as to prevent the breakdown or malfunction of the next-connected circuit. A laser light detection circuit has a differential amplifier that amplifies and outputs a signal corresponding to the intensity of laser light, a drive transistor having a base to which the output of the differential amplifier is applied, a second constant-current source connected to the emitter of the drive transistor, an output transistor having a base connected to the emitter of the drive transistor, a bypass transistor connected between the emitter of the drive transistor and the ground, and a control circuit. The control circuit forms a bypass current route from the second constant-current source to the ground through the bypass transistor by turning on the bypass transistor when the circuit switches from the operation stop mode to the operation mode.Type: GrantFiled: April 14, 2011Date of Patent: September 24, 2013Assignee: ON Semiconductor Trading, Ltd.Inventors: Rui Kurihara, Takahiro Kawashima
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Patent number: 8400221Abstract: An apparatus and method for biasing each amplifier of an amplification stage provides that the voltage across each current sensing element of each amplifier of the amplification stage is measured. For each pair of voltage measurements taken, a sum and difference is calculated, where the sum is processed to determine minima peaks and the difference is averaged. A portion of the sum term and the average of the difference term are summed to yield the individual bias current conducted by a first amplifier of the amplification stage. The difference between a portion of the sum term and the average of the difference term is calculated to yield the individual bias current conducted by the second amplifier of the amplification stage. The bias current conducted by the first and second amplifiers may then be individually modified manually, or conversely, may be modified automatically based upon the bias current measurements taken.Type: GrantFiled: February 16, 2011Date of Patent: March 19, 2013Assignee: Fender Musical Instruments CorporationInventor: Charles C. Adams
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Patent number: 8362649Abstract: Embodiments for at least one method and apparatus of a multi-use voltage regulator providing a supply voltage to a power amplifier and at least one other device are disclosed. One method includes generating a plurality of regulated voltage supplies from an unregulated voltage. An output signal power level of the power amplifier is determined. A one of the regulated plurality of voltage supplies and the unregulated voltage supply is selected as a power amplifier voltage supply for the power amplifier based at least in part on the output signal power level of the power amplifier. If the selected power amplifier voltage supply is one of the plurality of regulated voltage supplies, then the selected one of the plurality of regulated voltage supplies is simultaneously provided to the power amplifier and the at least one other device.Type: GrantFiled: June 18, 2010Date of Patent: January 29, 2013Assignee: R2 Semiconductor, Inc.Inventors: David Fisher, Ravi Ramachandran
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Patent number: 8189816Abstract: A computer controlled amplifier and speaker system includes a power conservation feature allowing ready adaptation to a variety of consumer vehicles, audio systems, and individual consumer purposes. The computer controlled amplifier and speaker system includes an audio-signal detection and power on/off feature and accepts multiple audio inputs and enables multiple audio outputs while also allowing ready adaptation to a variety of power sources. A plurality of power supply functions are readily adapted to supply power to the amplifier and speaker system enhancing user convenience. The disclosed system may be readily adaptable to a portable kit allowing achievement of similar power conservation goals in diverse settings.Type: GrantFiled: June 5, 2008Date of Patent: May 29, 2012Assignee: Wolo Mfg. Corp.Inventor: Stanley Solow
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Patent number: 8143949Abstract: Several push-pull linear hybrid class H amplifiers are disclosed. A split power rail provides a positive supply rail and a negative supply rail in response to a power supply control voltage. A push-pull amplifier stage is powered by the positive and negative supply rails. The amplifier stage receives an input signal and provides a corresponding amplified output signal. A power supply control circuit provides the power supply control voltage in response to the smaller of the positive and negative supply rails, and the input signal.Type: GrantFiled: December 24, 2009Date of Patent: March 27, 2012Assignee: Audera Acoustics Inc.Inventors: John B. French, Andrew J. Mason
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Patent number: 7944302Abstract: An apparatus and method for biasing each amplifier of an amplification stage provides that the voltage across each current sensing element of each amplifier of the amplification stage is measured. For each pair of voltage measurements taken, a sum and difference is calculated, where the sum is processed to determine minima peaks and the difference is averaged. A portion of the sum term and the average of the difference term are summed to yield the individual bias current conducted by a first amplifier of the amplification stage. The difference between a portion of the sum term and the average of the difference term is calculated to yield the individual bias current conducted by the second amplifier of the amplification stage. The bias current conducted by the first and second amplifiers may then be individually modified manually, or conversely, may be modified automatically based upon the bias current measurements taken.Type: GrantFiled: August 24, 2009Date of Patent: May 17, 2011Assignee: Fender Musical Instruments CorporationInventor: Charles C. Adams
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Patent number: 7907664Abstract: Systems and method to compress digital video based on human factors expressed as a desirability score are provided. A particular method includes passing a digital input signal through a pulse-width modulator and passing an output of the pulse-width modulator through a power switching device. An output of the power switching device has a plurality of pulses. The method includes receiving the output of the power switching device at a first input of a comparator and receiving a reference voltage at a second input of the comparator. The method includes determining a net signal based on an output of the comparator and determining a timing error signal based on the net signal and the digital input signal. The method also includes adjusting the digital input signal to compensate for harmonic distortion based at least in part on the timing error signal.Type: GrantFiled: December 7, 2009Date of Patent: March 15, 2011Assignee: Sigmatel, Inc.Inventors: Zukui Song, Michael Determan
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Publication number: 20110043278Abstract: An apparatus and method for biasing each amplifier of an amplification stage provides that the voltage across each current sensing element of each amplifier of the amplification stage is measured. For each pair of voltage measurements taken, a sum and difference is calculated, where the sum is processed to determine minima peaks and the difference is averaged. A portion of the sum term and the average of the difference term are summed to yield the individual bias current conducted by a first amplifier of the amplification stage. The difference between a portion of the sum term and the average of the difference term is calculated to yield the individual bias current conducted by the second amplifier of the amplification stage. The bias current conducted by the first and second amplifiers may then be individually modified manually, or conversely, may be modified automatically based upon the bias current measurements taken.Type: ApplicationFiled: August 24, 2009Publication date: February 24, 2011Applicant: FENDER MUSICAL INSTRUMENTS CORPORATIONInventor: Charles C. Adams
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Publication number: 20100171552Abstract: Several push-pull linear hybrid class H amplifiers are disclosed. A split power rail provides a positive supply rail and a negative supply rail in response to a power supply control voltage. A push-pull amplifier stage is powered by the positive and negative supply rails. The amplifier stage receives an input signal and provides a corresponding amplified output signal. A power supply control circuit provides the power supply control voltage in response to the smaller of the positive and negative supply rails, and the input signal.Type: ApplicationFiled: December 24, 2009Publication date: July 8, 2010Inventors: John B. French, Andrew J. Mason
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Patent number: 7571415Abstract: A layout of a power device is provided. The layout includes a substrate, a unit array, a plurality of first, second, third and fourth signal paths, and a first, second, third and fourth port. The unit array with a plurality of rows is disposed on the substrate. Each row of the unit array includes a plurality of units. The first and second signal paths on the substrate are disposed on a first side and a second side of corresponding odd-numbered rows of the unit array. The third and the fourth signal paths on the substrate are disposed above a corresponding row of the unit array. The first to fourth ports on the substrate are electrically connected to the first to fourth signal paths respectively.Type: GrantFiled: January 23, 2007Date of Patent: August 4, 2009Assignee: United Microelectronics Corp.Inventors: Houshang Aghahassan, Albert Kuo Huei Yen, Chung-Che Reed, Tsung-Chien Wu
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Patent number: 6970152Abstract: A column driver for a graphics display has reduced power consumption by sharing power between upper and lower column amplifiers. The upper column amplifier operates over an upper supply range, while the lower column amplifier operates over a lower supply range. The upper and lower amplifiers have the substantially the same quiescent operating current such that the total operating current for the column drivers in the graphics display is reduced by a factor of two. Each column amplifier can be driven over half of the power-supply range such that lower voltage amplifiers may be employed for the column driver amplifiers.Type: GrantFiled: November 5, 2002Date of Patent: November 29, 2005Assignee: National Semiconductor CorporationInventors: Marshall J. Bell, Christopher A. Ludden, Richard Alexander Erhart
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Patent number: 6759901Abstract: A dynamic sensor regulator that provides a mechanism for introducing desirable tonal artifacts in component-based guitar amplifier systems by inducing voltage fluctuations into the power supply of a preamplifier. The dynamic sensor regulator comprises a regulator circuit, connected to an amplifier that is connected to a converter circuit that is connected to a variable control circuit. The amplifier includes a floating bias circuit that dynamically adjusts the bias state of an output driving amplifier in response to signal fluctuations of the regulator output signal. A transformer is connected to the amplifier output and once the transformer's saturation point has been reached, the saturation of the transformer increases proportionally with the amplifier's input signal while the regulated output signal remains constant, emulating amplifier overload and saturation.Type: GrantFiled: November 21, 2002Date of Patent: July 6, 2004Assignee: VHT Amplification, Inc.Inventor: Steven M Fryette
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Patent number: 6703080Abstract: A radio frequency (RF) generator apparatus for a plasma processing system that is resistant to nonlinear load mismatch conditions is provided. The apparatus includes an RF oscillator configured to generate an RF signal, an RF amplifier responsive to the RF signal to produce a VHF RF signal having sufficient power to drive a plasma chamber load, and a VHF-band circulator coupled to the amplifier and configured to isolate nonlinearities of the plasma chamber load from the amplifier.Type: GrantFiled: May 20, 2002Date of Patent: March 9, 2004Assignee: ENI Technology, Inc.Inventors: Leonid E. Reyzelman, John E. Sortor
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Patent number: 6683496Abstract: The variable power supply to an amplifier in an electrical circuit is dynamically controlled through the use of a lookup table responsive to one or more operating conditions of the electrical circuit. The lookup table is indexed by one or more of the operating conditions and the amount of amplification to be applied to an input signal to the amplifier is determined. One embodiment of the invention comprises a television transmitter circuit including a power amplifier circuit capable of amplifying a variable frequency COFDM or 8VSB input signal where the amount of amplification applied to the input signal is dynamically controlled through the use of a lookup table as a function of the frequency of the input signal.Type: GrantFiled: August 20, 2001Date of Patent: January 27, 2004Assignee: Harris CorporationInventors: Peter John Poggi, Tim Dittmer, George Cabrera
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Patent number: 5909145Abstract: Sag of a power signal delivered to of an amplifier is controlled. The maximum amount of sag is limited to limit crossover distortion. A measuring circuit monitors an observed signal to generate a measured signal. A sag control circuit receives the measured signal and one or more input control signals, and in response generates a sag control signal. A regulator circuit receives the sag control signal and a raw power supply signal and in response generates a regulated DC power supply signal for the amplifier. The regulator circuit decreases the maximum power available to the amplifier as the sag control signal magnitude increases, so as to increase distortion and compression in the output signal (e.g., and achieve a "warm", "airy" or "forgiving" sound quality resembling or improving the sound of a vacuum tube amplifier).Type: GrantFiled: December 3, 1996Date of Patent: June 1, 1999Assignee: Maven Peal Instruments, Inc.Inventor: David G. Zimmerman
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Patent number: 5793252Abstract: 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: GrantFiled: December 9, 1996Date of Patent: August 11, 1998Assignee: Mesa Boogie, LimitedInventor: Randall C. Smith
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Patent number: 5635872Abstract: A regulated power supply control system with adjustable operating point and adjustable dynamic behavior for use with electronic power supply circuits, such as musical instrument amplifiers. The control system includes a measurement circuit (20) that generates a measured signal (22) based on an observed signal (18) in an amplifier (10); a sag control circuit (24) that generates a sag signal (32) based on the measured signal (22); a referenced circuit (34) that generates a static reference signal (38); and a regulator (44) that uses the static reference signal (38) and sag signal (32) to generate a regulated power supply output (14) that is used by the amplifier (10). The sag control circuit (24) permits adjustment of the sag signal 32 by a user-operated sag magnitude control (26), sag rate control (28), and sag recovery rate control (30).Type: GrantFiled: November 16, 1995Date of Patent: June 3, 1997Assignee: Maven Peal Instruments, Inc.Inventor: David G. Zimmerman
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Patent number: 5559469Abstract: A power output amplifier for use with electric guitar wherein the individual pairs of power tubes are of two or more differing types which may be selected by the user to operate alternately or simultaneously.Type: GrantFiled: March 14, 1994Date of Patent: September 24, 1996Inventor: Randall C. Smith
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Patent number: 5550509Abstract: An output power selection apparatus reduces the R.M.S. power output of a tube type amplifier without the use of solid state devices or ganged high or low power potentiometers.Type: GrantFiled: January 9, 1995Date of Patent: August 27, 1996Inventor: Salvatore J. Trentino
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Patent number: 5546046Abstract: A tonal altering feature for a tube type guitar audio amplifier provides apparatus enabling the selection of the method of output tube bias.Type: GrantFiled: January 9, 1995Date of Patent: August 13, 1996Inventor: Salvatore J. Trentino
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Patent number: 5170495Abstract: In a QAM microwave radio communications system an IF (intermediate frequency) input signal is amplified and predistorted, and the amplified IF signal is mixed with a local oscillator signal to produce an RF (radio frequency) signal which is amplified in a power amplifier for transmission, the predistortion compensating for non-linear gain of the power amplifier. Clipping in the power amplifier is controlled by down-converting part of the RF signal to produce an IF output signal, monitoring amplitude distortion of the RF signal by comparing the IF output signal with the IF input signal, and controlling the IF amplifier gain in dependence upon the monitored amplitude distortion.Type: GrantFiled: October 31, 1990Date of Patent: December 8, 1992Assignee: Northern Telecom LimitedInventors: John D. McNicol, Stephen G. Harman
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Patent number: 5022305Abstract: The distortion pedal for electric guitar and other electronic musical instruments employs vacuum tube circuitry operated by low voltage "battery eliminator" DC power supply. A pull-up resistor biasing circuit on the vacuum tube grid improves input and output impedance and circuit headroom while providing good control over the harmonic content and sustain.Type: GrantFiled: April 20, 1989Date of Patent: June 11, 1991Inventor: Brent K. Butler
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Patent number: 4719431Abstract: A push-pull power amplifier includes a pair of input terminals, a pair of output terminals, a pair of matched output tubes having cathode, plate, and grid terminals, and a pair of output power supplies, all of which are connected to form a bridge circuit. A floating bias supply is coupled between the grid and plate of both output tubes. A first feedback resistor couples the floating bias supply to the cathode of the first output tube. A second feedback resistor couples the floating bias supply to the cathode of the second output tube. The floating bias supply and feedback resistors provide degenerative feedback without affecting power gain.Type: GrantFiled: April 21, 1986Date of Patent: January 12, 1988Inventor: Ralph R. Karsten
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Patent number: 4636740Abstract: A biasing and control circuit for varying the output power delivered by the push-pull output stage of a power amplifier is disclosed. The biasing and control circuit incorporates both fixed and cathode biasing to allow output power to be varied without introducing distortion. A negative fixed biasing voltage is applied to the control grids of the vacuum tubes comprising the push-pull output stage, while the cathodes of such tubes are varied between ground and selected voltage levels above ground. To vary the voltage levels, the cathodes of the tubes are joined together by a common connection and coupled to ground through a variable impedance which when varied changes the conductivity of the output tubes, and thereby, the output power delivered by the amplier.Type: GrantFiled: July 7, 1986Date of Patent: January 13, 1987Inventor: Dennis L. Kager
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Patent number: 4593251Abstract: An electronic amplifying apparatus intended for sound reproduction and for music instrument amplification wherein two parallel amplifiers, working simultaneously, each in a different class of operation, are fed from a single driver or signal source and whose outputs are combined. In the preferred embodiment at least two pairs of push-pull vacuum tubes are required and they are arranged so that one pair operates Triode Class A while the other pair (or pairs) operates Pentode Class AB (or Class B). The circuit can then be optimized so that the desirable sonic characteristics of Class A Triode operation are imparted into the Class AB (or Class B) Pentodes which actually produce all or nearly all of the power. The output power waveform has the high power and efficiency typical of Class AB (or Class B) Pentode operation but without the detrimental sonic side effects, namely, there is the complete absence of crossover or "notch" distortion, and there is a "soft" gradual onset of clip.Type: GrantFiled: May 7, 1985Date of Patent: June 3, 1986Inventor: Randall C. Smith
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Patent number: 4532476Abstract: An electronic amplifying apparatus intended for sound reproduction and for music instrument amplification wherein two parallel amplifiers, working simultaneously, each in a different class of operation, are fed from a single driver or signal source and whose outputs are combined. In the preferred embodiment at least two pairs of push-pull vacuum tubes are required and they are arranged so that one pair operates Triode Class A while the other pair (or pairs) operates Pentode Class AB (or Class B). The circuit can then be optimized so that the desirable sonic characteristics of Class A Triode operation are imparted into the Class AB (or Class B) Pentodes which actually produce all or nearly all of the power. The output power waveform has the high power and efficiency typical of Class AB (or Class B) Pentode operation but without the detrimental sonic side effects, namely, there is the complete absence of crossover or "notch" distortion, and there is a "soft" gradual onset of clip.Type: GrantFiled: April 29, 1983Date of Patent: July 30, 1985Inventor: Randall C. Smith
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Patent number: 4449103Abstract: A method for amplifying electric signals, an amplifier circuit and application of this amplifier circuit as the modulator stage of a subsequent amplifier, employing a variable anode voltage for the purpose of improving the efficiency of amplifiers and particularly of high-power modulation amplifiers which are used, for example, in broadcast transmitters for the amplitude modulation of the radio-frequency output stage. From the modulation signal to be amplified, a control signal is derived in a control stage, this control signal being associated with the amplitude of the envelope of this modulation signal and being used for controlling the output voltage of a modulator/rectifier. The control signal is caused to follow the modulation signal within a presettable response time.Type: GrantFiled: December 4, 1981Date of Patent: May 15, 1984Assignee: BBC Brown, Boveri & Company, LimitedInventor: Bohumil Kyrian
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Patent number: 4353036Abstract: A complementary symmetry amplifier having variable gain control is used in an automatic gain control (AGC) system. The amplifier includes first and second field effect transistors of opposite conductivity type. Variable gain control is achieved by applying first and second differential control signals to respective gate electrodes of said first and second field effect transistors.Type: GrantFiled: August 29, 1980Date of Patent: October 5, 1982Assignee: RCA CorporationInventor: Merle V. Hoover
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Patent number: 3995226Abstract: An audio amplifier in which an output stage is coupled by a driver stage to an input stage which includes two antiphased sources of alternating current. The output stage includes two pentode vacuum tubes each having a cathode, a plate and a screen grid located between the cathode and the plate. Each tube has a control grid connected between the cathode and the screen grid and a suppressor grid connected between the screen grid and the plate, with the control grid and the suppressor grid being shunted to their respective cathodes. The driver stage includes a pair of transistors connected in a push-pull configuration with their emitters connected to the screen grids of said tubes to supply a relatively high value of alternating current to the screen grids which function as control grids for their respective tubes.Type: GrantFiled: June 10, 1976Date of Patent: November 30, 1976Inventor: David W. Berning