Audio power source with improved efficiency
An improved method of providing high burst power to audio amplifiers from limited power sources, using parallel power paths to increase system efficiency without need for a power path controller, thus utilizing a simplified circuit operation and maximizing average power available for both the amplifier and supporting circuitry.
1. Power delivery circuitry to deliver power to an audio device, the power delivery circuitry comprising:
a limited power input connected to the audio device;
a power transformer and a power storage device connected between the limited power input and the audio device;
a power limiter connected between the limited power input and the transformer to monitor input power to the transformer based on an input of a pulse width modulation (PWM) controller connected to the power limiter; and
an error amplifier connected to the power transformer and between the audio device and the PWM controller, wherein the error amplifier is configured to output, based on a detected current from the power transformer, a signal to the PWM controller to cause the power storage device to provide power to the audio device.
2. The power delivery circuitry of claim 1 , where the limited power input is selected from a group consisting of a power over Ethernet (PoE), USB, an AC inverter, an AC-DC converter, and a battery with an impedance above a certain value.
3. The power delivery circuitry of claim 1 , wherein the error amplifier is configured to output, based on the detected current from the power transformer, a signal to the PWM controller.
4. The power delivery circuitry of claim 3 , wherein the output of the signal to the PWM controller causes the power transformer to reduce output current.
5. The power delivery circuitry of claim 1 , wherein the PWM controller is connected between the power limiter and the audio source via an electrical path.
6. The power delivery circuitry of claim 5 , wherein the electrical path passes through the storage device and voltage regulator positioned between the limited power input and the audio device.
7. A method of dynamically controlling power in an audio system, the system comprising the steps of:
monitoring, via a power limiter connected between a power input and a power transformer, a power load requirement of an amplifier supplied by the power transformer;
communicating, via a current sensor, a current output of the transformer to an error amplifier;
receiving, via a pulse width modulation (PWN) controller, a signal from the error amplifier; and
causing, in response to the signal from the PWN controller, a power storage device to provide power to the amplifier.
8. The method of claim 7 , comprising comparing the power load requirement to a system reference value.
9. The method of claim 7 , wherein the power storage device is connected between the transformer and the amplifier.
10. The method of claim 7 , comprising reducing, in response a control signal from the PWN controller, the current output of the transformer.
11. A power management system for an audio system, comprising:
at least a first and a second DC output, wherein the first DC output provides power to an audio amplifier and wherein the second DC output provides power to a storage unit and a buck regulator;
an error amplifier;
a differential amplifier configured to communicate with the error amplifier to compare a reference voltage provided by a voltage reference shunt, where an output from the error amplifier is fed to a Pulse Width Modulation (PWM) controller; and
when an amplifier output requirement is above a power limit of the flyback converter, the power from the first DC output begins to fall and causes the buck regulator controller to engage the buck regulator to maintain voltage by power being drawn from the storage unit and pulled to the second DC output.
12. The power management system of claim 11 , comprising a connector that receives power from an Ethernet power source.
13. The power management system of claim 11 , wherein the first DC output provides power to an audio amplifier and to additional circuitry.
14. The power management system of claim 11 , wherein a peak primary current is detected from the PWM controller.
15. The power management system of claim 11 , comprising an optocoupler configured to receive error feedback.
16. The power management system of claim 15 , wherein the optocoupler is configured optimize dynamic load response.
17. The power management system of claim 11 , comprising a power switch configured to manage input voltage and transformer flyback voltage to a flyback converter.
18. The power management system of claim 17 , comprising a power switch that is controlled by the PWM controller.