Audio Power Management System with Dynamic Impedance Curves

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Solution Overview

Problem

Existing audio systems face challenges in managing loudspeaker impedance variations due to environmental and manufacturing deviations, leading to suboptimal performance and potential hardware damage, as they rely on fixed impedance curves that do not account for real-time operational conditions.

Innovation Solution

An audio power management system that customizes operational parameters in real-time using measured and estimated parameters, adjusting protective and operational thresholds to ensure safe and optimal operation of loudspeakers, amplifiers, and audio sources, by employing a calibration module, parameter computer, threshold comparators, and limiter to dynamically adjust audio signal processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fixed impedance curves are used for loudspeaker management, then system simplicity is maintained, but performance optimization and hardware protection are compromised due to impedance variations from environmental and manufacturing factors

Engineering Contradiction:
Improvehardware protectionVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic impedance curves that are continuously updated based on real-time measurements of loudspeaker parameters (DC resistance, resonance frequency, Qts) rather than using fixed manufacturer-specified curves. This allows the system to adapt to environmental changes and manufacturing variations, improving hardware protection while managing the complexity through automated measurement and update procedures

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback loops where the measured loudspeaker parameters are fed back to update the impedance curve, which then influences power management decisions. This closed-loop approach ensures that the system responds to actual loudspeaker conditions, enhancing reliability through continuous monitoring and adjustment of operational parameters

Inventive Principle:
Principle #23Feedback

2Measurement precision

If manufacturer-specified impedance curves are used, then ease of operation is maintained, but measurement precision and adaptability to actual loudspeaker conditions deteriorate

Engineering Contradiction:
Improveimpedance measurement accuracyVSAvoidsystem operation simplicity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs preliminary measurements of loudspeaker parameters (DC resistance, resonance frequency, Qts) during initialization or calibration phases to establish accurate baseline values before normal operation begins. This preliminary action enables precise impedance curve generation without requiring continuous complex measurements during playback, balancing measurement precision with operational simplicity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system automatically measures and updates its own impedance curves without requiring manual intervention or external calibration equipment. The power management system itself performs the measurements and generates the customized curves, making the process self-service and maintaining ease of operation while achieving high measurement precision through repeated real-time measurements

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If real-time parameter measurement and customization is implemented, then adaptability and performance optimization improve, but device complexity and measurement requirements increase

Engineering Contradiction:
Improvesystem adaptabilityVSAvoidmeasurement system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system uses a single power management module that performs multiple functions: measuring loudspeaker parameters, generating impedance curves, calculating safe operating thresholds, and controlling power delivery. This multi-functional approach increases adaptability while managing complexity by consolidating measurement and control functions into one integrated system rather than separate dedicated components

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically changes operational parameters (power thresholds, impedance curves) based on measured loudspeaker characteristics and environmental conditions. By focusing parameter changes on the essential electrical characteristics needed for safe operation rather than attempting to control all physical parameters, the system achieves high adaptability with manageable measurement complexity

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2797340B1Audio power management system
Publication Date: 2020.04.29 HARMAN INT IND INC
  • EP2797340B1 patent drawingFigure 1
  • EP2797340B1 patent drawingFigure 2
  • EP2797340B1 patent drawingFigure 3

AI summary

An audio power management system manages operation of audio devices in an audio system. The audio power management system includes a parameter computer, a threshold comparator and a limiter. Audio signals generated with the audio system may be provided to the audio power management system. Based on a measured actual parameter of the audio signal, such as a real-time actual voltage and/or a real-time actual current, the parameter computer can derive estimated operational characteristics of audio devices, such as a loudspeaker included in the audio system. The threshold comparator may use the estimated operational characteristics to develop a threshold and manage operation of one of more devices in the audio system by monitoring the measured actual parameter, and selectively directing the limiter to adjust the audio signal, or another device in the audio system to protect or optimize performance.