Power supply with low standby loss

• US 20070115695A1
• Filed: 12/29/2005
• Published: 05/24/2007
• Est. Priority Date: 11/21/2005
• Status: Active Grant

• Current Assignee: Delta Electronics Incorporated
• Original Assignee: Delta Electronics Incorporated
• Inventors: Lou, Junshan, Gan, Hongjian, Feng, Jiangtao
• Granted Patent: US 7,532,493 B2
• Time in Patent Office: Days
• US Class Current: 363/16
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• 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 present invention discloses a power supply device with low standby loss. The power supply device comprises a main power converter and an auxiliary power converter. The main power converter comprises a bulk capacitor. The main power converter connects parallelly with the auxiliary power converter. When the power supply device is in a standby mode, the main converter is turned off and the auxiliary converter provides the output to the outputting load and the bulk capacitor. Moreover, when the power supply device is in a normal mode, the main converter and the auxiliary converter together provide the output to an outputting load. Under a normal mode, the main converter provides most of the power and the auxiliary converter operates in a power-limited finite value such that the topology of the power supply device achieves a low standby loss.

Claims

1. A power supply comprising:

a main power converter connected to an input power source, having at least one output for connecting a load, and including a bulk capacitor as an intermediate energy storage component;

an auxiliary power converter connected to said input power source, having a first output connected to said output of said main power converter, and having a second output connected to said bulk capacitor of said main power converter; and

a control circuit to control said main power converter and said auxiliary power converter.

2. A power supply as in claim 1, wherein said main power converter and said auxiliary power converter supply power to said load when the load current is greater than a predetermined current level.

3. A power supply as in claim 1, wherein said auxiliary power converter supplies power to said load and provides a regulated voltage to said bulk capacitor when the load current is smaller than said predetermined current level.

4. A power supply as in claim 3, wherein said main power converter is disabled.

5. A power supply as in claim 1, wherein said input power source comprises a DC power source.

6. A power supply as in claim 1, wherein said input power source comprises an AC power source.

7. A power supply as in claim 1, wherein said main power converter comprises a front-end stage and a DC/DC output stage.

8. A power supply as in claim 7, wherein said front-end stage comprises a power-factor-correction converter.

9. A power supply as in claim 1, wherein said main power converter comprises a single-stage PFC converter.

10. A power supply as in claim 1, wherein said auxiliary power converter comprising:

an input-filter capacitor;

a first output-filter capacitor connected across said first output;

a second output-filter capacitor connected across said second output;

a transformer having a primary winding and a secondary winding, one terminal of said secondary winding connected to the negative terminal of said first output-filter capacitor;

two switches periodically coupling and decoupling said primary winding and said input-filter capacitor;

two rectifiers coupling said primary winding and said second output-filter capacitor; and

a third rectifier coupling said secondary winding and said first output-filter capacitor.

11. A power supply as in claim 10, wherein a substantial proportion of voltages of said second output and said first output of said auxiliary power converter is determined by the turns ratio of said primary winding and said secondary winding of said transformer.

12. A power supply as in claim 1, wherein said auxiliary power converter comprising:

an input-filter capacitor;

a first output filter capacitor connected across said first output;

a second output filter capacitor connected across said second output;

a transformer having a primary winding and a secondary winding, wherein, one terminal of said primary winding is connected to the positive terminal of said input-filter capacitor, and one terminal of said secondary winding is connected to the negative terminal of said first output-filter capacitor;

a switch periodically coupling and decoupling said primary winding and said input-filter capacitor;

a first rectifier coupling said primary winding and said second output-filter capacitor;

a fourth capacitor, one terminal of said fourth capacitor connected to the other terminal of said secondary winding;

a second rectifier coupling said fourth capacitor and said secondary winding; and

a third rectifier coupling said fourth capacitor and said first output-filter capacitor.

13. A power supply as in claim 12, wherein a substantial proportion of voltages of said second output and said first output of said auxiliary power converter is determined by the turns ratio of said primary winding and said secondary winding of said transformer.

14. A power supply as in claim 1, wherein said auxiliary power converter comprising:

an input-filter capacitor;

a first output filter capacitor connected across said first output;

a second output filter capacitor connected across said second output;

a transformer having a primary winding, a first secondary winding, and a second secondary winding, wherein, one terminal of said primary winding is connected to the positive terminal of said input-filter capacitor, one terminal of said first secondary winding is connected to the negative terminal of said first output-filter capacitor, and one terminal of said second secondary winding is connected to the negative terminal of said second output-filter capacitor;

a switch periodically coupling and decoupling said primary winding and said input-filter capacitor;

a first rectifier coupling said first secondary winding and said first output-filter capacitor; and

a second rectifier coupling said second secondary winding and said second output-filter capacitor.

15. A power supply as in claim 14, wherein a substantial proportion of voltages of said second output and said first output of said auxiliary power converter is determined by the turns ratio of said primary winding and said secondary winding of said transformer.