CONTROLLER FOR A POWER CONVERTER AND METHOD OF OPERATING THE SAME

• US 20140254215A1
• Filed: 04/24/2014
• Published: 09/11/2014
• Est. Priority Date: 08/29/2011
• Status: Abandoned Application

• Current Assignee: Power Systems Technologies Company Limited (Flex, Ltd.)
• Original Assignee: Power Systems Technologies Company Limited (Flex, Ltd.)
• Inventors: Brinlee, Antony, Berghegger, Ralf Schroeder genannt
• Application Number:
  US14/260,467
• Publication Number:
  US 20140254215A1
• Time in Patent Office: Days
• US Class Current: 363/21.15
• CPC Class Codes: H02M 1/4258 using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage H02M1/4241 takes precedence
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take 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

A control system for a power converter with reduced power dissipation and method of operating the same. In one embodiment, the control system includes a first controller coupled to a primary winding of a transformer and configured to control a duty cycle of a power switch to regulate an output characteristic of the power converter. The control system also includes a second controller configured to provide a signal to one of a secondary winding of the transformer and a circuit element spanning an isolation boundary of the transformer in response to a dynamic change of the output characteristic to trigger the first controller to initiate the duty cycle for the power switch.

Claims

1. A control system for a power converter, comprising:

a first controller coupled to a primary winding of a transformer and configured to control a duty cycle of a power switch to regulate an output characteristic of said power converter; and

a second controller configured to provide a signal to one of a secondary winding of said transformer and a circuit element spanning an isolation boundary of said transformer in response to a dynamic change of said output characteristic to trigger said first controller to initiate said duty cycle for said power switch.

2. The control system as recited in claim 1 wherein said circuit element is one of a Y-capacitor and a pulse transformer.

3. The control system as recited in claim 1 wherein said signal is a pulsed feedback signal.

4. The control system as recited in claim 1 wherein said second controller is configured to provide said signal during a complementary duty cycle of said power converter.

5. The control system as recited in claim 1 wherein said second controller is configured to provide said signal in response to a decrease of said output characteristic below a threshold level.

6. The control system as recited in claim 1 wherein said second controller comprises a one-shot pulse generator and a switching lockout circuit.

7. The control system as recited in claim 6 wherein said one-shot pulse generator causes a switch to conduct to provide said signal.

8. The control system as recited in claim 6 wherein said switching lockout circuit disables said one-shot pulse generator when said power switch is actively switching.

9. A power converter, comprising:

a transformer including a primary winding and a secondary winding;

a power switch coupled to said primary winding; and

a control system, comprising;

a first controller coupled to said primary winding and configured to control a duty cycle of said power switch to regulate an output characteristic of said power converter, and

a second controller configured to provide a signal to one of said secondary winding and a circuit element spanning an isolation boundary of said transformer in response to a dynamic change of said output characteristic to trigger said first controller to initiate said duty cycle for said power switch.

10. The power converter as recited in claim 9 wherein said circuit element is one of a Y-capacitor and a pulse transformer.

11. The power converter as recited in claim 9 wherein said signal is a pulsed feedback signal.

12. The power converter as recited in claim 9 wherein said second controller is configured to provide said signal during a complementary duty cycle of said power converter.

13. The power converter as recited in claim 9 wherein said second controller is configured to provide said signal in response to a decrease of said output characteristic below a threshold level.

14. The power converter as recited in claim 9 wherein said second controller comprises a one-shot pulse generator and a switching lockout circuit.

15. The power converter as recited in claim 14 wherein said one-shot pulse generator causes a switch to conduct to provide said signal.

16. The power converter as recited in claim 14 wherein said switching lockout circuit disables said one-shot pulse generator when said power switch is actively switching.

17. A method of operating a power converter, comprising:

controlling a duty cycle of a power switch to regulate an output characteristic of said power converter with a first controller coupled to a primary winding of a transformer; and

providing a signal to one of a secondary winding of said transformer and a circuit element spanning an isolation boundary of said transformer with a second controller in response to a dynamic change of said output characteristic to trigger said first controller to initiate said duty cycle for said power switch.

18. The method as recited in claim 17 wherein said signal is a pulsed feedback signal.

19. The method as recited in claim 17 wherein said second controller provides said signal during a complementary duty cycle of said power converter.

20. The method as recited in claim 17 wherein said second controller provides said signal in response to a decrease of said output characteristic below a threshold level.