Speaker Amplifier Power Regulation Using Impedance Feedback
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Solution Overview
Problem
Smart amplifiers with analog digital converters are costly and not the most cost-effective solution for protecting speakers from thermal and mechanical damage due to size constraints, which limit the current and voltage they can handle.
Innovation Solution
A method and system that use an application processor to generate an impedance measuring signal, measure current and voltage, and regulate power supply based on impedance, reducing the need for expensive digital converters by using low-frequency signals and analog communication to prevent speaker damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If smart amplifiers with analog digital converters are used to measure current and voltage, then speaker protection against thermal and mechanical damage is improved, but device cost increases
Solution Approach 1:
The patent extracts the expensive analog digital converter from the amplifier circuit and replaces it with a processor that generates test signals and calculates impedance using digital signal processing. This removes the costly component while maintaining speaker protection functionality through software-based impedance measurement.
Solution Approach 2:
The patent replaces the hardware-based analog digital converter with a software-based digital signal processing approach. The processor uses digital algorithms to measure impedance by analyzing voltage and current signals, substituting mechanical/electronic conversion hardware with computational methods.
2Area of moving object
If the coil size is reduced to meet area constraints, then device compactness is improved, but the current and voltage handling capability deteriorates
Solution Approach 1:
The patent implements preliminary monitoring of speaker impedance to detect potential overload conditions before they cause damage. By continuously measuring impedance and comparing it against safe operating thresholds, the system can prevent excessive current or voltage from reaching the small coil, protecting it despite its reduced size.
Solution Approach 2:
The patent employs feedback control by measuring speaker impedance in real-time and using this information to regulate power delivery. The processor adjusts the output signal based on impedance measurements, ensuring the small coil operates within safe current and voltage limits while maintaining audio quality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively regulates power to the speaker, preventing thermal and mechanical damage while reducing costs by eliminating the need for costly digital converters, allowing for safer operation within size constraints.
Implementation Method 1
determining an impedance of the speaker based on the measured current and voltage
Implementation Method 2
When electrical current runs through a coil of a speaker, a magnetic field is created. The magnetic field generated by the coil interacts with other magnetic fields of the speaker, which in turn moves the coil to vibrate air and generate the sound waves.
Data Source
AI summary
A method of regulating power supply to a speaker and a system for regulating power supply to a speaker comprising a generating of a low frequency signal output to the speaker, sensing a current and a voltage of the speaker after the low frequency signal is output to the speaker, measuring an impedance of the speaker based on the current and voltage, determining a temperature of the speaker and comparing with a threshold value, and lowering a power supply to the speaker where the temperature is above the threshold value.