Voltage converter

• US 6,657,872 B2
• Filed: 02/26/2002
• Issued: 12/02/2003
• Est. Priority Date: 03/01/2001
• Status: Expired due to Fees

• Current Assignee: PAI Capital LLC (ABB Limited)
• Original Assignee: Power-One AG (ABB Limited)
• Inventors: Chapuis, Alain, Gammenthaler, Peter
• Primary Examiner(s): NGUYEN, MATTHEW VAN
• Application Number:
  US10/082,625
• Publication Number:
  US 20020122321A1
• Time in Patent Office: 644 Days
• Field of Search: 363/16, 363/17, 363/21.01, 363/21.04, 363/21.06, 363/21.14, 363/56.02, 363/97, 363/98, 363/131, 363/132
• US Class Current: 363/17
• CPC Class Codes: H02M 3/33592 having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

The invention concerns a voltage converter of a flux converter type with a self-regulating synchronous rectifier in the secondary circuit related to a transformer (17), with a capacitor device (C₁; C₁, C₂) being provided, for driving an active switching element (V₁, V₂) of the synchronous rectifier, which is charged by means of an auxiliary winding (W₁, W₂) of the transformer in the secondary circuit, and its charge is applied to a control terminal of the active switching element by means of a semiconductor element (D₁, D₂; 30, 32), with the capacitor device being implemented in such a way that the charge allows synchronous switching operation of the active switching element.

Claims

1. A voltage converter of a flux converter type having a self-regulating synchronous rectifier in the secondary circuit related to a transformer (17),

characterized in that

a capacitor device (C₁;

C₁, C₂) is provided for driving an active switching element (V₁, V₂) of the synchronous rectifier,

which is charged by means of an auxiliary winding (W₁, W₂) of the transformer in the secondary circuit, and its charge is applied to a control terminal of the active switching element by means of a semiconductor element (D₁, D₂;

30, 32),

with the capacitor device being implemented in such a way that the charge allows synchronous switching operation of the active switching element.

2. A voltage converter according to claim 1, characterized in that a capacitance of the capacitor device is a multiple of an effective capacitance of the control terminal, particularly 5 to 10 times this quantity.

3. A voltage converter according to claim 1, characterized in that the voltage converter has a balanced configuration in the primary circuit and a current doubler configuration in the secondary circuit.

4. A voltage converter according to claim 3, characterized in that the voltage converter has a half-bridge configuration in the primary circuit and a current doubler configuration in the secondary circuit.

5. A voltage converter according to claim 3, characterized in that the voltage converter has a full-bridge configuration in the primary circuit and a current doubler configuration in the secondary circuit.

6. A voltage converter according to claim 3, characterized in that the voltage converter has a phase shift configuration in the primary circuit and a current doubler configuration in the secondary circuit.

7. A voltage converter according to claim 3, characterized in that the voltage converter has a balanced configuration in the primary circuit and a middle point configuration in the secondary circuit.

8. A voltage converter according to claim 3, characterized in that the voltage converter has a half-bridge configuration in the primary circuit and a middle point configuration in the secondary circuit.

9. A voltage converter according to claim 3, characterized in that the voltage converter has a full-bridge configuration in the primary circuit and a middle point configuration in the secondary circuit.

10. A voltage converter according to claim 3, characterized in that the voltage converter has a phase shift configuration in the primary circuit and a middle point configuration in the secondary circuit.

11. A voltage converter according to claim 1, characterized in that, for a pair of active switching elements (V₁ V₂) of the synchronous rectifier which realizes two rectifier arms, a corresponding pair of auxiliary windings (W₁, W₂) of the transformer is each provided with an assigned semiconductor element (D₁, D₂), which are connected with a shared capacitor as a capacitor device (C₁).

12. A voltage converter according to claim 1, characterized in that the semiconductor element is implemented as a transistor.

13. A voltage converter according to claim 12, characterized in that the transistor is a MOSFET.

14. A voltage converter according to claim 1, characterized in that, for each of a pair of active switching elements (V₁ V₂) of the synchronous rectifier realizing two rectifier arms, an associated auxiliary winding (W₁, W₂) of the transformer and, as a semiconductor element, a transistor (30, 32) are provided, with the capacitor device having a capacitor (C₁, C₂) connected in series between the control terminal of each relevant switching element of the pair of active switching elements and the associated auxiliary winding, and a control terminal of each of the transistors being connected with one connection node between the auxiliary winding and the capacitor of an opposing rectifier arm.

15. A voltage converter according to claim 14, characterized by apparatus (34, 36) for voltage limiting connected between the capacitor and the control terminal of an associated switching element of the pair of active switching elements.

16. A voltage converter according to claim 15, characterized in that the apparatus for voltage limiting is realized as a channel of a transistor driven with a bias voltage (U_G).

17. A voltage converter according to claim 16, characterized in that the transistor is a MOSFET.