Method for extending power supply hold-up time by controlling a transformer turn ratio

Patent metadata

Field	Value
Publication number	US-9455637-B2
Application number	US-201414588228-A
Country	US
Kind code	B2
Filing date	Dec 31, 2014
Priority date	Dec 31, 2014
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

In one embodiment a method of extending power supply hold-up time by controlling a transformer turn ratio may include an input capacitor receiving an input voltage of a transformer unit. A first control transistor may switch a first transformer winding to an on state in response to the input voltage being above a voltage threshold level. The first control transistor may switch the first transformer winding to an off state in response to the input voltage being below the voltage threshold level. A second control transistor may switch a second transformer winding to an on state in response to the input voltage being below the voltage threshold level, wherein the first transformer winding and the second transformer winding may include separate windings located on a same side of a magnetic core of the transformer unit. In an embodiment the transformer unit may include a power supply unit.

First claim

The invention claimed is:

1. A method of extending power supply hold-up time by controlling a transformer turn ratio, comprising:
receiving, with an input capacitor, an input voltage of a transformer unit;
switching, with a first control transistor, a first transformer winding to an on state in response to the input voltage being above a voltage threshold level;
switching, with the first control transistor, the first transformer winding to an off state in response to the input voltage being below the voltage threshold level; and
switching, with a second control transistor, a second transformer winding to an on state in response to the input voltage being below the voltage threshold level, wherein the first transformer winding and the second transformer winding comprise separate windings located on a same side of a magnetic core of the transformer unit.

2. The method of claim 1 , wherein the same side of the magnetic core comprises an input side of the transformer unit.

3. The method of claim 1 , wherein the same side of the magnetic core comprises an output side of the transformer unit.

4. The method of claim 1 , wherein the first transformer winding comprises thirteen (13) turns and the second transformer winding comprises ten (10) turns.

5. The method of claim 1 , wherein the voltage threshold level comprises three hundred and thirty (330) Volts.

6. The method of claim 1 , wherein:
the first transformer winding further comprises a plurality of separate windings; and
the second transformer winding further comprises a plurality of separate windings.

7. The method of claim 1 , wherein the transformer unit further comprises a power supply unit.

8. A system for extending power supply hold-up time by controlling a transformer turn ratio, comprising:
an input capacitor configured to receive an input voltage of a transformer unit;
a first control transistor configured to:
switch a first transformer winding to an on state in response to the input voltage being above a voltage threshold level; and
switch the first transformer winding to an off state in response to the input voltage being below the voltage threshold level; and

a second control transistor configured to switch a second transformer winding to an on state in response to the input voltage being below the voltage threshold level, wherein the first transformer winding and the second transformer winding comprise separate windings located on a same side of a magnetic core of the transformer unit.

9. The system of claim 8 , wherein the same side of the magnetic core comprises an input side of the transformer unit.

10. The system of claim 8 , wherein the same side of the magnetic core comprises an output side of the transformer unit.

11. The system of claim 8 , wherein the first transformer winding comprises thirteen (13) turns and the second transformer winding comprises ten (10) turns.

12. The system of claim 8 , wherein the voltage threshold level comprises three hundred and thirty (330) Volts.

13. The system of claim 8 , wherein:
the first transformer winding further comprises a plurality of separate windings; and
the second transformer winding further comprises a plurality of separate windings.

14. The system of claim 8 , wherein the transformer unit further comprises a power supply unit.

15. An apparatus for extending power supply hold-up time by controlling a transformer turn ratio, comprising:
an input capacitor configured to receive an input voltage of a transformer unit;
a first control transistor configured to:
switch a first transformer winding to an on state in response to the input voltage being above a voltage threshold level; and
switch the first transformer winding to an off state in response to the input voltage being below the voltage threshold level; and

a second control transistor configured to switch a second transformer winding to an on state in response to the input voltage being below the voltage threshold level, wherein the first transformer winding and the second transformer winding comprise separate windings located on a same side of a magnetic core of the transformer unit.

16. The apparatus of claim 15 , wherein the same side of the magnetic core comprises an input side of the transformer unit.

17. The apparatus of claim 15 , wherein the same side of the magnetic core comprises an output side of the transformer unit.

18. The apparatus of claim 15 , wherein the first transformer winding comprises thirteen (13) turns and the second transformer winding comprises ten (10) turns.

19. The apparatus of claim 15 , wherein the voltage threshold level comprises three hundred and thirty (330) Volts.

20. The apparatus of claim 15 , wherein:
the first transformer winding further comprises a plurality of separate windings; and
the second transformer winding further comprises a plurality of separate windings.

Assignees

• Dell Products Lp
• Dell Products Lp

Inventors

• Hung Tsai-Fu
• Tsai Hung-Hsun
• Lai Yu-Hung
• Chou Kuang-Hao

Classifications

• H02M3/33507 Primary

  with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence) · CPC title

• H02M1/0096

  Means for increasing hold-up time, i.e. the duration of time that a converter's output will remain within regulated limits following a loss of input power · CPC title

• H02M1/0058

  by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero (using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826) · CPC title

• H02M3/3378

  in a push-pull configuration of the parallel type (H02M3/3374 takes precedence) · CPC title

• Y02B70/10

  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 · CPC title