POWER SUPPLY FOR LIMITED POWER SOURCES AND AUDIO AMPLIFIER USING POWER SUPPLY

• US 20090016549A1
• Filed: 07/18/2008
• Published: 01/15/2009
• Est. Priority Date: 01/23/2006
• Status: Active Grant

• Current Assignee: Audera Acoustics Inc.
• Original Assignee: Audera Acoustics Inc.
• Inventors: Mason, Andrew John, French, John B.
• Granted Patent: US 8,577,061 B2
• Time in Patent Office: Days
• US Class Current: 381/120
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H03F 1/025 by using a signal derived from the input signal
• CPC Class Codes: H03F 2203/21196 the supply voltage of a power amplifier being switchable controlled
• CPC Class Codes: H03G 3/004 Control by varying the supply voltage

Abstract

A power supply for limited power sources and an audio amplifier using the power supply comprising power sources to provide an output power signal that can be used by load with a high peak to average power requirement ratio. When such power sources are used to power devices that have a high peak to average power consumption, the average power output of the device is severely limited if the peak power is kept below the power supply limits of the limited power source.

Claims

1. A power supply comprising:

a power input terminal for receiving an input power signal at a source voltage from a limited power source;

an energy storage element for storing energy;

a step-up converter coupled to the power input terminal to receive the input power signal and for providing a storage power signal to the energy storage element at a storage voltage, and wherein the step-up converter isolates the source voltage at the input terminal from the storage voltage at the energy storage element;

a power output terminal; and

wherein the energy storage element is coupled to the step-up converter for receiving power and wherein the energy storage element in coupled to the output terminal for providing an output power signal to a load.

2. The power supply of claim 1 wherein the step-up converter includes a source power sensing circuit to measure the power level of the input power signal and includes a power limiting circuit to reduce the power level of the input power signal if the power level of the input power signal exceeds a threshold.

3. The power supply of claim 2 wherein the threshold is chosen based on the power supply limitations of the limited power source.

4. The power supply of claim 2 wherein the threshold is a proportion of the power rating of the limited power source.

5. The power supply of claim 1 wherein the step-up converter includes a power sensing circuit to measure the source voltage, and includes a power limiting circuit to reduce the power level of the input power signal if the source voltage falls below a threshold.

6. The power supply of claim 1 further comprising a step-down converter coupled between the energy storage element and the power output terminal, wherein the step-down converter receives power from the energy storage element at the storage voltage and provides output power signal at the power output terminal at a supply voltage, wherein the storage voltage is higher than the supply voltage.

7. A power supply comprising:

a power input terminal;

an first energy storage element for storing energy at a first storage voltage;

a second energy storage element for storing energy at a second storage voltage;

a two output step-up converter coupled to the power input terminal to receive an input power signal from a limited power source at a source voltage and to provide a first storage power signal to the first energy storage element at the first storage voltage and to provide a second storage power signal to the second energy storage element at a second storage voltage;

a power output terminal for providing an output power signal to a load, wherein the first energy storage element is coupled to the power output terminal;

a load input signal terminal; and

a controller coupled to the load input signal terminal to receive a load power signal and for selectively coupling the second energy storage element to the power output terminal in response to the load power signal.

8. The power supply of claim 7 further comprising a switch for coupling the first and second energy storage elements such that when the switch is open, the output power signal is provided by the first energy storage element, and when the switch is closed, the output power signal is provided by both the first and second storage elements, and wherein the controller couples the second energy storage element to the power output terminal by closing the switch.

9. An audio amplification circuit comprising:

a power supply including;

a power input terminal

a step-up converter coupled to the power input terminal to receive an input power signal at a source voltage from a power limited source;

an energy storage block, wherein the step-up converter provides a storage power signal to the energy storage block;

one or more power output terminals;

a converter; and

an audio amplification stage including;

one or more audio input terminals;

one or more audio amplifiers, wherein each audio amplifier is coupled to the power output terminals to receive the one or more output power signals and is coupled to one of the audio input terminals to receive a corresponding input audio signal, and wherein the audio amplification stage provides an amplified audio signal corresponding to each input audio signal,

wherein the converter is coupled;

to the energy storage block to draw power from the step-up converter and the energy storage block;

to the audio input terminals to receive the input audio signals; and

to the power output terminals to provide an output power signal at each of the power output terminals, wherein the magnitude of the output power signal at each of the power output terminals is determined, at least in part, by the magnitude of the input audio signals.

10. The audio amplification circuit of claim 9 wherein the converter is a tracking power converter and wherein the power converter generates the output power signals in response to magnitude of the largest of the input audio signals.

11. The audio amplification circuit of claim 10 wherein the power converter generates the output power signals corresponding the envelope of the largest of the input audio signals.

12. The audio amplification circuit of claim 9 wherein the power converter generates a pair of split rail output power signals.