Patents by Inventor Eric Mendenhall

Eric Mendenhall has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20120223747
    Abstract: A triangular waveform generator includes a square waveform clock circuit and an integrating circuit. The integration circuit receives input from the square waveform clock circuit and generates a triangular waveform output. A feedback circuit is operatively connected to the integrating circuit to reduce the audio band noise content in the triangular waveform output. The feedback circuit acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.
    Type: Application
    Filed: May 10, 2012
    Publication date: September 6, 2012
    Applicant: RGB SYSTEMS, INC.
    Inventor: ERIC MENDENHALL
  • Patent number: 8253491
    Abstract: A method and apparatus for power conversion in a class D amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails. This minimizes the effects of off side charging and rail sag, as well as achieving good line regulation, while allowing use of very small, low value output capacitors.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: August 28, 2012
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Patent number: 8198924
    Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.
    Type: Grant
    Filed: April 20, 2011
    Date of Patent: June 12, 2012
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Publication number: 20110193597
    Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.
    Type: Application
    Filed: April 20, 2011
    Publication date: August 11, 2011
    Applicant: RGB Systems, Inc.
    Inventor: ERIC MENDENHALL
  • Publication number: 20110182087
    Abstract: A method and apparatus for power conversion in a class D amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails. This minimizes the effects of off side charging and rail sag, as well as achieving good line regulation, while allowing use of very small, low value output capacitors.
    Type: Application
    Filed: November 18, 2010
    Publication date: July 28, 2011
    Inventor: Eric Mendenhall
  • Patent number: 7948281
    Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: May 24, 2011
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Patent number: 7839215
    Abstract: A method and apparatus for power conversion in a class D amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails. This minimizes the effects of off side charging and rail sag, as well as achieving good line regulation, while allowing use of very small, low value output capacitors.
    Type: Grant
    Filed: June 12, 2009
    Date of Patent: November 23, 2010
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Publication number: 20090309658
    Abstract: A method and apparatus for power conversion in a class D amplifier is provided. The power conversion is achieved using synchronous rectifiers in a regulated half bridge power supply, taking the sum of the positive and negative rails as feedback, in order facilitate energy transfer between positive and negative output rails. This minimizes the effects of off side charging and rail sag, as well as achieving good line regulation, while allowing use of very small, low value output capacitors.
    Type: Application
    Filed: June 12, 2009
    Publication date: December 17, 2009
    Applicant: RGB SYSTEMS, INC.
    Inventor: ERIC MENDENHALL
  • Patent number: 7501889
    Abstract: The present invention provides lossless switching by configuring the output inductor so that the ripple current amplitude at load conditions results in small negative current during switching. The reconfigured output inductor results in increased ripple current amplitude. This increased ripple amplitude may be further controlled using zero ripple steering techniques to eliminate ripple at the output capacitor. A ripple steering technique involves adding a secondary output to the class D amplifier which steers the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Grant
    Filed: July 28, 2006
    Date of Patent: March 10, 2009
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Publication number: 20080180141
    Abstract: A triangular waveform generator includes a square waveform clock circuit and an active integrator. The active integrator receives input from the square waveform clock circuit and generates a triangular waveform output. An active feedback network is operatively added to the active integrator to reduce the audio band noise content in the triangular waveform output. The feedback network acts as a DC balance without significant sacrifice in the linearity of the triangular waveform output.
    Type: Application
    Filed: January 24, 2008
    Publication date: July 31, 2008
    Inventor: ERIC MENDENHALL
  • Patent number: 7253683
    Abstract: Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. A secondary output is added to the amplifier for the purpose of steering the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Grant
    Filed: October 17, 2006
    Date of Patent: August 7, 2007
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Patent number: 7253684
    Abstract: Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. A secondary output is added to the amplifier for the purpose of steering the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Grant
    Filed: October 17, 2006
    Date of Patent: August 7, 2007
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Publication number: 20070115055
    Abstract: The present invention provides lossless switching by configuring the output inductor so that the ripple current amplitude at load conditions results in small negative current during switching. The reconfigured output inductor results in increased ripple current amplitude. This increased ripple amplitude may be further controlled using zero ripple steering techniques to eliminate ripple at the output capacitor. A ripple steering technique involves adding a secondary output to the class D amplifier which steers the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Application
    Filed: July 28, 2006
    Publication date: May 24, 2007
    Applicant: RGB SYSTEMS, INC.
    Inventor: Eric Mendenhall
  • Publication number: 20070085604
    Abstract: Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. A secondary output is added to the amplifier for the purpose of steering the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Application
    Filed: October 17, 2006
    Publication date: April 19, 2007
    Applicant: RGB SYSTEMS, INC.
    Inventor: Eric Mendenhall
  • Publication number: 20070063773
    Abstract: Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. A secondary output is added to the amplifier for the purpose of steering the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Application
    Filed: October 17, 2006
    Publication date: March 22, 2007
    Applicant: RGB SYSTEMS, INC.
    Inventor: Eric Mendenhall
  • Publication number: 20070022482
    Abstract: The invention is directed to an in vivo functional genomics screen for extracting functional information from a global gene expression profiling dataset in a high-throughput manner.
    Type: Application
    Filed: June 13, 2006
    Publication date: January 25, 2007
    Inventors: Craig Eckfeldt, Eric Mendenhall, Stephen Ekker, Catherine Verfaillie
  • Patent number: 7167048
    Abstract: Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. A secondary output is added to the amplifier for the purpose of steering the switching ripple away from the main output thus substantially relieving the main output from a major artifact of prior art Class D amplifiers.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: January 23, 2007
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Patent number: 7161428
    Abstract: Class D amplifiers are used for their high efficiency, but they have some undesirable characteristics that limit their useable bandwidth, one of these being the residual switching frequency ripple. Embodiments of the present invention comprise methods and apparatuses for reducing the switching frequency ripple using a technique known herein as ripple steering. The zero ripple class D amplifier is used in a hybrid system comprising a linear amplifier. The hybrid Class D amplifier is modified for extended bandwidth and lowered distortion by the addition of a linear current source feeding output capacitor. The low frequency bandwidth limit on the linear current source is matched to the high frequency bandwidth limit on the Class D current source, resulting in a composite linear/switching current source with bandwidth extended to the high frequency bandwidth limit of the linear current source.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: January 9, 2007
    Assignee: RGB Systems, Inc.
    Inventor: Eric Mendenhall
  • Patent number: 7061740
    Abstract: A system and method for protecting an output transistor in an audio amplifier output stage includes a protection circuit that protects the output transistor from excessive currents and voltages, and does not interfere with the normal operation of the output transistor. The protection circuit generates an estimate of the power dissipated by the output transistor, applies this estimate to an electrical analog of the thermal time constants of the transistor to obtain an estimate of the temperature differential between junction and case, compares this differential to a limit, which is a function of transistor case temperature.
    Type: Grant
    Filed: June 26, 2003
    Date of Patent: June 13, 2006
    Assignee: Gibson Guitar Corp.
    Inventor: Eric Mendenhall
  • Patent number: 7012542
    Abstract: A multicolor function indicator light system is provided for an audio amplifier or similar electronic equipment. A sensor circuit monitors operation of the equipment. An indicator light device has a plurality of different color outputs. A control logic circuit receives input signals from the sensor and controls the indicator light device so that different sensed modes of operation of the electronic equipment are indicated by different color outputs of the indicator light device.
    Type: Grant
    Filed: April 4, 2003
    Date of Patent: March 14, 2006
    Assignee: Gibson Guitar Corp.
    Inventors: Mark H. Powell, David W. Seaton, Eric Mendenhall