Efficient power supply post regulation

• US 5,119,284 A
• Filed: 10/11/1991
• Issued: 06/02/1992
• Est. Priority Date: 04/05/1990
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: General Electric Company
• Inventors: Fisher, Rayette A., El-Hamamsy, Sayed-Amr A.
• Primary Examiner(s): BEHA JR, WILLIAM
• Application Number:
  US07/775,203
• Time in Patent Office: 235 Days
• Field of Search: 363/21, 363/26, 363/65, 363/67, 363/69, 363/70, 363/80, 363/82, 363/90, 363/47, 363/48, 307/34, 323/266
• US Class Current: 363/48
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control

Abstract

High efficiency, post regulation of auxiliary outputs in multiple output-power supplied is provided by connecting a regulating switching device in parallel with a filter inductor connected in the current path from the rectifiers to the output terminal. For minimum output power for that auxiliary output, the switching device is held off at all times. When increased power is required, the switching device is turned on for a short period during each cycle of the inductor voltage. The switching system may be configured to conduct current from the output end of the inductor to the input end of the inductor or vice versa or either one selectively, in accordance with the particular regulation scheme chosen. Efficiency is maximized since current flows in the switching device for only a small portion of each cycle of the inductor voltage.

Claims

1. A power supply comprising:

a transformer having a primary winding and master and auxiliary tapped secondary windings;

master and auxiliary rectification systems, respectively connected across said master and auxiliary secondary windings for rectifying the ac signals provided by said secondary windings;

said master rectification system comprising means for rectifying ac signals appearing at the terminals of said master secondary winding, a master output filter and a master output terminal;

said power supply including a regulation system for controlling a signal applied to said primary winding of said transformer in a manner to regulate the output at said master output terminal;

said auxiliary rectification system comprising means for rectifying ac signals appearing at the terminals of said auxiliary secondary winding, an auxiliary output filter and an auxiliary output terminal, said auxiliary output filter comprising an auxiliary filter inductor connected in the current path from said auxiliary rectification system to said auxiliary output terminal; and

an auxiliary output voltage regulation system including an auxiliary regulating switching system connected in parallel with said auxiliary filter inductor, said regulating switching system being capable of holding off voltage in both polarities.

2. The power supply recited in claim 1 wherein said auxiliary regulating switching system is a bidirectional switching device.

3. The power supply recited in claim 1 wherein said auxiliary regulating switching system comprises:

a switching device capable of controlling current conduction in a first polarity; and

a diode connected in series with said switching device, said diode being oriented to prevent current flow in said switching device in a second polarity.

4. The power supply recited in claim 3 wherein:

said diode is oriented to enable current flow therethrough from the output terminal end of said inductor to the rectification system end of said inductor.

5. The power supply recited in claim 3 wherein:

said diode is oriented to enable current flow therethrough from the rectification system end of said inductor to the output terminal end of said inductor.

6. The power supply of claim 5 wherein:

said auxiliary rectification system includes at least one rectifying device; and

said auxiliary output voltage regulation system further includes control means for controlling the turn-ON time of said switching device to occur when at least one of said rectifying devices is conducting, just prior to the period when all of said rectifying devices are off, thereby rapidly charging the filter capacitor.

7. The power supply recited in claim 1 wherein said auxiliary regulating switching system comprises:

a switching device capable of holding off voltage in a first polarity; and

a diode connected in series with said switching device, said diode being oriented to prevent current flow in said switching device in a second polarity.

8. The power supply recited in claim 7 wherein:

said diode is oriented to enable current flow therethrough from the output terminal end of said inductor to the rectification system end of said inductor.

9. The power supply recited in claim 7 wherein:

said diode is oriented to enable current flow therethrough from the rectification system end of said inductor to the output terminal end of said inductor.

10. The power supply of claim 9 wherein:

said auxiliary rectification system includes at least one rectifying device; and

said auxiliary output voltage regulation system further includes control means for controlling the turn-ON time of said switching device to occur when at least one of said rectifying devices is conducting, just prior to the period when all of said rectifying devices are off, thereby rapidly charging the filter capacitor.

11. The power supply recited in claim 1 wherein:

said auxiliary regulating switching system comprises a self-commutating switching device.

12. The power supply recited in claim 11 wherein:

said switching device is oriented to enable current flow therethrough from the output terminal end of said inductor to the rectification system end of said inductor.

13. The power supply recited in claim 11 wherein:

said switching device is oriented to enable current flow therethrough from the rectification system end of said inductor to the output terminal end of said inductor.

14. The power supply recited in claim 11 wherein:

said auxiliary output voltage regulation system includes means for providing a turn-ON control signal to said auxiliary regulating switching system for causing said self-commutating switching device to switch from its non-conductive state to its conductive state.

15. The power supply recited in claim 14 wherein:

said auxiliary rectification system includes at least one rectifying device; and

said means for providing is configured to provide said turn-ON control signal during a period when all of said at least one rectifying devices are off.

16. The power supply recited in claim 14 wherein:

said auxiliary secondary winding has first and second ends and a tap, said tap being connected to a reference potential;

said auxiliary rectification system includes first and second rectifying devices, respectively connected in the current paths between said first and second ends of said secondary winding and said filter inductor; and

said means for providing is configured to provide said turn-ON control signal during a period when said first and second rectifying devices are both off.

17. The power supply recited in claim 11 wherein:

said switching device is a regenerative device.

18. The power supply recited in claim 3 wherein:

said means for rectifying includes at least one rectifying device; and

said auxiliary output voltage regulation system includes means for providing a switching control signal to said auxiliary regulating switching system for causing said auxiliary regulating switching system to switch between its non-conductive and conductive states when all of said at least one rectifying devices are off.

19. The power supply recited in claim 4 wherein said auxiliary output voltage regulation system includes:

an auxiliary filter capacitor connected between said auxiliary output terminal and a reference potential; and

means for sensing the voltage across said auxiliary filter capacitor.