Switching power supply system with pre-regulator for circuit or personnel protection devices

• US 20070114981A1
• Filed: 11/21/2005
• Published: 05/24/2007
• Est. Priority Date: 11/21/2005
• Status: Abandoned Application

• Current Assignee: Square D Company (Schneider Electric SE)
• Original Assignee: Square D Company (Schneider Electric SE)
• Inventors: Meehleder, Steven, Vasquez, Jacinto
• Application Number:
  US11/284,194
• Publication Number:
  US 20070114981A1
• Time in Patent Office: Days
• US Class Current: 323/266
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

A linear pre-regulator for cascading with a switching regulator for providing a load current for a circuit or personnel protection device includes a transistor for providing a series variable resistance when a load current changes. The series variable resistance includes a control node, and a control part maintains a substantially fixed voltage at the control node when the current drawn by the switching regulator changes. A storage part may be included to provide a voltage at a drain of a transistor forming the series variable resistance during an OFF-to-ON transition of the transistor.

Claims

1. A switching power supply system for a circuit or personnel protection device, comprising:

an input stage for outputting a rectified signal;

a switching regulator for outputting a DC output signal;

a pre-regulator in cascade between the input stage and the switching regulator, the pre-regulator including a transistor for providing variable resistance, and a control part for maintaining a fixed voltage at a gate of the transistor; and

an output stage for filtering noise from the DC output signal.

2. The switching power supply system of claim 1, wherein the transistor is connected in a source follower mode.

3. The switching power supply system of claim 1, wherein the pre-regulator is a linear pre-regulator.

4. The switching power supply system of claim 1, wherein the control part includes a zener diode connected between the gate of the transistor and a ground.

5. The switching power supply system of claim 1 wherein the control part includes a voltage dividing resistor connected between an output of the input stage and the gate of the transistor.

6. The switching power supply system of claim 1, further including a current limiting resistor between the control part and a drain of the transistor for limiting a current from the source of the transistor to the switching regulator.

7. The switching power supply system of claim 1, further including a circuit or personnel protection device coupled to said output stage.

8. The switching power supply system of claim 7, wherein said circuit or personnel protection device is a circuit breaker or a surge protector.

9. The switching power supply system of claim 1 implemented as an ASIC.

10. The switch power supply system of claim 1 which includes a storage part for providing a voltage at a drain of the transistor during an OFF-to-ON transition of the transistor.

11. A system board for a circuit or personnel protection device, comprising:

an integrated circuit receiving a load current;

a switching power supply system; and

an interface circuit for interfacing the switching power supply system to the integrated circuit,

wherein the switching power supply system includes a linear pre-regulator in cascade with a switching regulator, the linear regulator including a transistor for providing a variable resistance, a control part for maintaining a fixed voltage at a gate of the transistor, and a storage part for providing a voltage at a drain of the transistor during an OFF-to-ON transition of the transistor.

12. A switching power supply system for a circuit or personnel protection device, comprising:

an input stage for outputting a rectified signal;

a switching regulator for outputting a DC output signal;

a linear pre-regulator coupled between the input stage and the switching regulator, the pre-regulator including a series variable resistance that decreases in response to increases in a current drawn by the switching regulator and increases in response to decreases in the current drawn, said series variable resistance including a control node, and a control part for maintaining a substantially fixed voltage at said control node; and

an output stage coupling the DC output signal to a load.

13. The switching power supply system of claim 12, wherein the series variable resistance includes a transistor.

14. A method of providing a load current to a circuit or personnel protection device, comprising:

pre-regulating a rectified signal through a transistor cascaded with a switching regulator for providing a variable resistance when a load current changes; and

maintaining a fixed voltage at a gate of the transistor when the load current changes.

15. The method of claim 14 which further includes storing a voltage for providing the stored voltage at a drain of the transistor during an OFF-to-ON transition of the transistor.

16. A method of supplying power to a circuit or personnel protection device, comprising:

outputting a rectified signal at an input stage;

receiving said rectified signal in a switching regulator and outputting a DC output signal from said switching regulator;

linearly pre-regulating said rectified signal between said input stage and said switching regulator with a series variable resistance that decreases in response to increases in a current drawn by the switching regulator and increases in response to decreases in the current drawn; and

coupling said DC output signal to a load.

17. The method of claim 16, wherein said series variable resistance includes a transistor having a gate, and further including maintaining a fixed voltage at said gate.