Patents Assigned to Purifi APS
  • Patent number: 11956612
    Abstract: The present invention relates to a motor for an electrodynamic loudspeaker, comprising a magnetic circuit assembly arranged about a motor axis. The magnetic circuit assembly comprises: an outer magnet, a magnetically permeable top plate, a magnetically permeable bottom plate, a center pole piece and an air gap for receipt of a voice coil. The air gap is formed by an inner axially extending wall of the magnetically permeable top plate facing an axially extending peripheral wall section of the center pole piece to define a width, a bottom, a top and height of the air gap. The magnetic circuit assembly additionally comprises outwardly projecting magnetically permeable member arranged above the top of the air gap. The center pole piece comprises a magnetic member extending axially from at least the bottom of the air gap to a magnetically permeable bottom member or to the magnetically permeable bottom plate.
    Type: Grant
    Filed: February 12, 2020
    Date of Patent: April 9, 2024
    Assignee: PURIFI APS
    Inventors: Lars Risbo, Carsten Tinggaard, Morten Halvorsen, Bruno Putzeys
  • Patent number: 11405007
    Abstract: An amplifier, such as a Class D amplifier, having one or more feedback loops comprising a path from the input to the primary amplifier input, where the paths comprise a low pass filter and a compensator which is disabled when the primary amplifier clips.
    Type: Grant
    Filed: July 20, 2018
    Date of Patent: August 2, 2022
    Assignee: PURIFI APS
    Inventors: Bruno Putzeys, Lars Risbo
  • Patent number: 11258411
    Abstract: A Class D amplifier having an integrating primary amplifier with an internal feedback, the amplifier further comprising a feedback loop with a filter of at least second order.
    Type: Grant
    Filed: July 20, 2018
    Date of Patent: February 22, 2022
    Assignee: PURIFI APS
    Inventors: Bruno Putzeys, Lars Risbo
  • Patent number: 11082017
    Abstract: An amplifier comprising a gain stage with a feedback network comprising two ports between which at least three capacitors are connected in series and between each pair of capacitors a resistor is connected to a predetermined voltage. The gain stage is provided in a feedback loop over a primary amplifier.
    Type: Grant
    Filed: July 20, 2018
    Date of Patent: August 3, 2021
    Assignee: PURIFI APS
    Inventors: Bruno Putzeys, Lars Risbo
  • Patent number: 10728659
    Abstract: The present invention relates in one aspect to a method of controlling or limiting diaphragm excursion of a loudspeaker. The method comprising steps of receiving a first audio signal and deriving an excursion signal representing diaphragm excursion of the electrodynamic loudspeaker from the first audio signal. The method additionally comprises deriving an excursion envelope from the excursion signal and applying a second audio signal, derived from the first audio signal, to an input of an adjustable low-frequency suppressor. The second audio signal is filtered by the adjustable low-frequency suppressor to selectively attenuate low-frequency components based on the excursion envelope to produce a processed audio signal with reduced low-frequency content.
    Type: Grant
    Filed: May 2, 2017
    Date of Patent: July 28, 2020
    Assignee: Purifi APS
    Inventors: Bruno Putzeys, Lars Risbo
  • Publication number: 20190149920
    Abstract: The present invention relates in one aspect to a method of controlling or limiting diaphragm excursion of a loudspeaker. The method comprising steps of receiving a first audio signal and deriving an excursion signal representing diaphragm excursion of the electrodynamic loudspeaker from the first audio signal. The method additionally comprises deriving an excursion envelope from the excursion signal and applying a second audio signal, derived from the first audio signal, to an input of an adjustable low-frequency suppressor. The second audio signal is filtered by the adjustable low-frequency suppressor to selectively attenuate low-frequency components based on the excursion envelope to produce a processed audio signal with reduced low-frequency content.
    Type: Application
    Filed: May 2, 2017
    Publication date: May 16, 2019
    Applicant: Purifi APS
    Inventors: Bruno PUTZEYS, Lars RISBO