Synchronized controlled oscillation modulator

• US 7,119,629 B2
• Filed: 12/16/2002
• Issued: 10/10/2006
• Est. Priority Date: 12/21/2001
• Status: Expired due to Term

• Current Assignee: Bang & Olufsen ICEpower A/S
• Original Assignee: Bang & Olufsen ICEpower A/S
• Inventors: Hansen, Jesper Lind, Nielsen, Karsten
• Primary Examiner(s): Chang, Joseph
• Application Number:
  US10/498,314
• Publication Number:
  US 20050068121A1
• Time in Patent Office: 1,394 Days
• Field of Search: 331/2, 331/46, 331/50, 332/109, 332/127, 332/149, 332/162, 332/106, 330/10
• 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 (SCOM), comprising:

at least one controlled oscillation modulator (COM) having a non-hysteresis comparator, a switching stage and a negative feedback loop adapted to achieve conditions for controlled oscillation of a predetermined frequency by means of at least two poles, and

a synchronizing device connected to said COM modulator.

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

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

4. A modulator according to claim 1, comprising a second COM modulator, said synchronizing device 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 device comprises a circuit consisting of R, RC or C components.

6. A modulator according to claim 5, wherein said synchronizing device comprises:

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-device comprises an active circuit, preferably including at least one high pass filter.

8. A modulator according to claim 1, wherein the modulator is 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, wherein the modulator is implemented in a PSCPWM system, without common mode high frequency spectral contributions in the three level pulse output.

10. A modulator according to claim 1, wherein the modulator is 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, further 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 a limiter device to control the PWM modulation depth.

13. A modulator according to claim 1, wherein the modulator is implemented in a general power conversion system, in the general power conversion system is in a DC-AC audio power conversion system.

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