Audio power source with improved efficiency

• US 10,608,607 B2
• Filed: 01/09/2018
• Issued: 03/31/2020
• Est. Priority Date: 01/09/2018
• Status: Active Grant

• Current Assignee: Biamp Systems, LLC
• Original Assignee: Biamp Systems, LLC
• Inventors: Baretich, David F., Broadley, Simon J.
• Primary Examiner(s): Nguyen, Patricia T
• Application Number:
  US15/866,367
• Publication Number:
  US 20190214956A1
• Time in Patent Office: 812 Days
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/0025 Sequential battery discharge in systems with a plurality of batteries
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/285 Single converters with a plurality of output stages connected in parallel parallel operation of a plurality of converters in dc distribution networks H02J1/10
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H02M 7/066 particular circuits having a special characteristic
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/3264 in audio amplifiers
• CPC Class Codes: H03F 2200/03 the amplifier being designed for audio applications
• CPC Class Codes: H03F 3/181 Low-frequency amplifiers, e.g. audio preamplifiers
• CPC Class Codes: H03F 3/183 with semiconductor devices only
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals

Abstract

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.

Claims

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, a power storage device, and a voltage regulator 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, the PWM controller being connected between the power limiter and the audio source via a first electrical path that passes through the storage device and the voltage regulator; and

an error amplifier connected to the power transformer and between the audio device and the PWM controller, the error amplifier being configured to output, based on a detected current from the power transformer, a signal to the PWM controller to cause the power transformer to reduce output current and 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 the group consisting of a power over Ethernet (PoE), USB, an AC inverter, a AC-DC converter, and a battery with an impedance above a certain value.

3. A method of dynamically controlling power in an audio system, the system comprising the steps of:

a. 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;

b. comparing the power load requirement to a first system reference value;

c. communicating, via a current sensor, a current output of the transformer to an error amplifier;

d. receiving, via a PWM controller a signal from the error amplifier controller;

e. reducing, in response a control signal from a pulse width modulation (PWN) controller, an output of the power transformer current; and

f. causing, in response to control signal from the PWN controller, a power storage device connected between the transformer and the amplifier to provide power to the amplifier.

4. A power management system for an audio system, comprising:

a. A connector for receiving power from an Ethernet power source;

b. At least a first and a second DC outputs, wherein the first DC output provides power to an audio amplifier and to additional circuitry and wherein the second output provides power to a storage unit and a buck regulator;

c. A power switch capable of managing input voltage and transformer flyback voltage to a flyback converter, which power switch is controlled by a pulse width modulation (PWM)controller, and from which a peak primary current is detected;

d. An error amplifier;

e. An optocoupler which receives error feedback and optimizes dynamic load response;

f. A differential amplifier which communicates with to error amplifier to compare a reference voltage provided by a voltage reference shunt, where an output from the error amplifier is fed to the PWM controller; and

wherein

g. if 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 drawing power from the storage unit and pulling power to the second DC output.