公开(公告)号：EP2097978A2

公开(公告)日：2009-09-09

申请号：EP07849423.4

申请日：2007-12-11

Applicant: Bang & Olufsen IcePower A/S

Inventor： KRAGH, Morten ,  NIELSEN, Ole Neis

IPC: H03K7/08

CPC classification number: H03K7/08 ,  H03F3/217

Abstract: The present invention relates to the application of a free-tunning clock signal in a pulse- width modulator (PWM) Specifically there is disclosed an integrated circuit comprising a pulse-width modulator (2) for converting an input signal (6) into a pulse-width-modulated signal (8), the pulse-width modulator (2) being clocked by a clock signal (4) generated by a clock generator (3) which generates a free-running clock signal In a preferred embodiment of the invention, the clock generator (3) is provided in the same integrated circuit (1), such as a chip, as the digital pulse-width modulator (2).

公开(公告)号：EP1456944B1

公开(公告)日：2009-04-29

申请号：EP02790577.7

申请日：2002-12-16

Applicant: Bang & Olufsen IcePower A/S

Inventor： NIELSEN, Karsten ,  LIND HANSEN, Jesper

IPC: H03F3/38

CPC classification number: H03F3/217 ,  H02M3/1584 ,  H03F2200/351

Abstract: A synchronized controlled oscillation modulator (SCOM) , comprising at least one, Controlled Oscillation Modulator (5) , and synchronizing means (1, 6) connected to said COM modulator. The modulator can comprise several COM modulators, and the synchronizing means can be arranged between the COM systems, so that the oscillation modulator signal is used as synchronization signal. The invention provides significant advantages in performance, topological simplification, improved robustness, stability and efficiency compared to prior art.

公开(公告)号：EP1987585A1

公开(公告)日：2008-11-05

申请号：EP07705648.9

申请日：2007-02-23

Applicant: Bang & Olufsen IcePower A/S

Inventor： PETERSEN, Lars

IPC: H03F3/217

CPC classification number: H03F3/217 ,  H03F3/2173 ,  H03F2200/03 ,  H03F2200/504 ,  Y10T307/858

Abstract: An audio power conversion system (3) comprising a power supply (1) having a positive supply rail (100) and a negative supply rail (200) for supplying power to a single ended class D amplifier (2). The system further comprises a supply pump reduction circuit (6) connected to the supply rails (100, 200) and adapted to redistribute a pumping charge from said power supply by forcing a current-flow from a rail with a higher voltage to a rail with a lower voltage. According to the current invention, the redistribution circuit is arranges to always distribute charge from the rail with the higher voltage. This means that for practical circuits the pump canceling occurs continuously and is not confined to every other cycle as for the prior art.

公开(公告)号：EP1671420A2

公开(公告)日：2006-06-21

申请号：EP04769576.2

申请日：2004-10-07

Applicant: Bang & Olufsen IcePower A/S

Inventor： NIELSEN, Karsten ,  FENGER, Lars, Michael

IPC: H03F3/217

CPC classification number: H03F3/68 ,  H03F1/305 ,  H03F3/217 ,  H03F2200/03 ,  H03F2200/351

Abstract: A power conversion system comprising at least one Pulse Modulated Amplifier (1), including a pulse modulator for generating a pulse modulated signal based on a reference input (vi), a switching power stage arranged to amplify the pulse modulated signal, and a control system arranged to compensate for power supply voltage variations, and a voltage supply (2) providing drive voltage (Vs) to each amplifier, wherein said voltage supply (2) is provided with said input reference (vi), and arranged to provide a first drive voltage component (Vs) tracking an amplified absolute value of the input reference (vi). Pulse area modulation according to the invention will result in improved efficiency and at the same time ensure lower levels of EMI, as the mean amplitude of the PAM signal is lowered.

公开(公告)号：EP1588484A1

公开(公告)日：2005-10-26

申请号：EP03780526.4

申请日：2003-11-14

Applicant: Bang & Olufsen IcePower A/S

Inventor： FENGER, Lars, Michael

IPC: H03F3/217 ,  H03F3/38

CPC classification number: H03F3/217 ,  H03F1/32 ,  H03F3/38

Abstract: A pulse modulation power converter comprising a forward path including a forward block (15), a switching stage (11) for amplifying an output from the forward block, and an output filter (12) for low pass filtering an output signal from the switching stage, a global feedback path (13), connected to the low pass filtered output signal, comprising a global feedback block (18, 19) for generating a feedback signal, and means (14) for subtracting said feedback signal from an input signal, and feeding the result to said forward path. The global feedback block and/or forward block includes means for compensating at least a portion of a phase lag of said output filter, and means for obtaining a 180 degrees phase lag at a switching frequency, thereby achieving conditions for a controlled oscillation at said switching frequency. The control system combines the advantages of the self-oscillation technology with a high gain, wide-band control loop for suppressing non-linearities. This will lead to a better performing system in terms of total harmonic distortion and noise.

公开(公告)号：EP1391137A1

公开(公告)日：2004-02-25

申请号：EP02730566.3

申请日：2002-05-16

Applicant: Bang & Olufsen IcePower A/S

Inventor： NIELSEN, Karsten

IPC: H04R1/00 ,  H04R19/00

CPC classification number: H04R3/00 ,  H03F3/2173

Abstract: The present invention relates to an apparatus for converting an audio signal from a source (25) into audio waves, comprising a modulator (17), for modulating said audio signal, an amplifying switching stage (15), for amplifying a modulated audio signal supplied from the modulator, and a transducer (19). The transducer is connected directly to the switching stage, and is arranged to convert a pulse train from the switching stage into audio waves. Further, the modulator, the switching stage and the conversion means are integrated mechanically and electrically in one operational unit, being connectable directly to a mains power supply (12). By this electrical integration, no separate filtering is required, but instead the inherent qualities of the transducer are used for accomplishing filtering of the pulse train.