Power supply transient response improving

• US 8,350,537 B2
• Filed: 03/04/2010
• Issued: 01/08/2013
• Est. Priority Date: 03/04/2010
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: Sheen, Timothy
• Primary Examiner(s): Behm, Harry
• Application Number:
  US12/717,216
• Publication Number:
  US 20110215776A1
• Time in Patent Office: 1,041 Days
• Field of Search: 323/207, 323285-286, 363/39, 363 44- 46, 363/48, 307/103
• US Class Current: 323/207
• CPC Class Codes: G05F 1/46 wherein the variable actually regulated by the final control device is dc G05F1/625 takes precedence
• CPC Class Codes: G05F 1/70 Regulating power factor; Regulating reactive current or power
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators

Abstract

A power factor correcting power supply. The power factor correcting power supply includes a controlled current source for providing electrical power of a regulated current and a regulated voltage to a first output terminal, a voltage comparison current controller, and a control circuit responsive to the current at the output terminal, the control circuit coacting with the voltage comparison current controller to cause the controlled current source to increase or decrease the current at the first output terminal.

Claims

1. A power factor correcting power supply, comprising:

first and second output terminals for accommodating terminals of an electrical load;

a controlled current source for providing electrical power of a regulated current and a regulated voltage to the first output terminal;

a voltage comparison current controller; and

a control circuit responsive to the current at the first output terminal, the control circuit coacting with the voltage comparison current controller to cause the controlled current source to increase or decrease the current at the first output terminal, the control circuit comprising;

a bypass capacitor coupling the first output terminal and the second output terminal;

a current sensor measuring the combined current flowing through the bypass capacitor and to the first output terminal;

a voltage sensor sensing voltage at the first output terminal or at a point separated from the first output terminal by a resistance; and

a derived current calculator operationally coupled to the current sensor and to the voltage sensor, to determine the current at the output terminal exclusive of current flowing in the bypass capacitor.

2. The power factor correcting power supply of claim 1, wherein the derived current calculator determines the current at the output terminal exclusive of current flowing in the bypass capacitor according to

3. The power factor correcting power supply of claim 1, further comprising:

a power factor correcting waveform shaper coupling the controlled current source with the derived current calculator, the power factor correcting waveform shaper receiving as input information about an AC line input having an AC line cycle to the power factor correcting power supply and providing a signal to control output current averaged over the AC line cycle.

4. The power factor correcting power supply of claim 3,

wherein the current sensor and the voltage sensor measure the current and the voltage, respectively, at a point separated from the first output terminal by a resistance;

and

wherein the derived current calculator further derives a voltage correction that modifies a voltage measurement that is provided to the voltage comparison current controller.

5. The power factor correcting power supply of claim 4, wherein the voltage correction is determined according to

Voltage_Correction=I_S×

R

where I_S is sensed current at the current and R is the resistance.

6. A method for operating a power factor correcting power supply, comprising:

providing, by a controlled current source a voltage and current at a first output terminal;

sensing a combined current flowing through a bypass capacitor and to the first output terminal;

sensing a voltage;

determining the current at the first output terminal;

based on the determined current at the first output terminal, increasing or decreasing the current at the first output terminal

wherein the determining the current at the first output terminal comprises deriving the current at the first output terminal exclusive of the current flowing in the bypass capacitor based on the sensed current and the sensed voltage.

7. The method of claim 6, wherein the deriving the current at the first output terminal exclusive of the current flowing in a bypass capacitor comprises calculating the current according to

8. The method of claim 6, wherein sensing the current and sensing the voltage comprises:

sensing the current and the voltage at a point separated from the first output terminal by a resistance; and

wherein the method of operating the power factor correcting power supply further comprises deriving a voltage correction that modifies a voltage measurement that is provided to a voltage comparison current controller.

9. The method of claim 8, comprising deriving the voltage correction according to

Voltage_Correction=I_S×

R

where I_S is the sensed current and R is the resistance.

10. The method of claim 6, further comprising providing the sensed current and the sensed voltage to a derived current calculator, wherein the derived current calculator is configured to derive the current at the first output terminal exclusive of the current flowing in the bypass capacitor based on the sensed current and the sensed voltage.