Synchronized controlled oscillation modulator

• US 20050068121A1
• Filed: 12/16/2002
• Published: 03/31/2005
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Bang & Olufsen ICEpower A/S (Bang & Olufsen A/S)
• Original Assignee: Bang & Olufsen ICEpower A/S (Bang & Olufsen A/S)
• Inventors: Lind Hansen, Jesper, Nielsen, Karsten
• Granted Patent: US 7,119,629 B2
• Time in Patent Office: Days
• US Class Current: 332/106
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H03F 2200/351 Pulse width modulation being used in an amplifying circuit
• CPC Class Codes: H03F 3/217 Class D power amplifiers; Switching amplifiers

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.

Claims

1. A synchronized controlled oscillation modulator, comprising at least one controlled oscillation modulator, and synchronizing means connected to said COM modulator.

2. A modulator according to claim 1, wherein the synchronizing means comprises an oscillation signal generator.

3. A modulator according to claim 1, synchronized by another SCOM modulator comprising any oscillating modulator signal with the frequency of the wanted idle switching frequency.

4. A modulator according to claim 1, comprising a second COM modulator, said synchronizing means being connected between forward paths of said COM modulators and arranged to synchronize the COM modulators with each other.

5. A modulator according to claim 3, wherein said synchronization means comprise a circuit consisting of R, RC or C components.

6. A modulator according to claim 5, wherein said synchronizing means comprise:

a first and a second series resistances (RA, RB), a parallel resistor (Rosc), and

a parallel capacitor (Cosc), wherein said first series resistance is connected to a first end of the parallel capacitor and parallel resistor, and said second series resistance is connected to a second end of the parallel capacitor and parallel resistor, and wherein said first and second series resistances are connected to a comparator in the forward path of each modulator respectively.

7. A modulator according to claim 3, wherein said-synchronization-means comprise an active circuit, preferably including at least one high pass filter.

8. A modulator according to claim 1, extended by an additional SCOM modulator driven in a full-bridge configuration to achieve a three-level pulse output.

9. A modulator according to claim 8, implemented in a PSCPWM system, without common mode high frequency spectral contributions in the three level output.

10. A modulator according to claim 1, implemented in a multi-loop MECC (N,M) control system for enhanced noise suppression, where N and M are integers representing the number of local and global control loops respectively.

11. A modulator according to claim 1, comprising N COM modulators synchronized by an additional synchronization signal or by a common COM signal of said COM modulators.

12. A modulator according to claim 1, further comprising limiter means to control the PWM modulation depth.

14. A modulator according to claim 1, used to drive an electrodynamic transducer load directly.

15. A modulator according to claim 1, said-COM modulator comprising a comparator, a power amplification stage, and a negative feedback loop adapted to achieve conditions for controlled oscillation at a predetermined frequency.

13. A modulator according to claim implemented in a general power conversion system, in particular in DC-AC audio power conversion systems.