Acoustic Transducer Controller for Power and Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional acoustic transducer systems face challenges in efficiently controlling magnetizing current for magnetic coils, leading to inefficiencies, increased power consumption, and acoustic distortion, particularly in automotive applications where voltage source amplifiers are used, and lack suitable protection and diagnostics.
Innovation Solution
An acoustic transducer arrangement that includes a controller to manage the current in both stationary and moving coils, optimizing power usage by varying current levels based on audio signal intensity, using a combination of current and voltage sources to improve transient response and accuracy, and incorporating protection and diagnostics for electronic components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional acoustic transducer systems use stationary and moving coils with time varying signals, then audible sound is produced corresponding to the input audio signal, but power consumption increases and efficiency decreases
Solution Approach 1:
The patent applies periodic action by using a stationary coil to generate an alternating magnetic flux that periodically magnetizes and demagnetizes the magnetic material in the air gap. This periodic magnetization allows the moving coil to operate more efficiently by converting electrical energy to mechanical energy only when needed, rather than maintaining continuous magnetic fields. The stationary coil current is modulated to create this periodic magnetic flux, reducing overall power consumption while maintaining acoustic output.
Solution Approach 2:
The stationary coil performs preliminary action by pre-magnetizing the magnetic material in the air gap before the moving coil needs to generate force. This preliminary magnetization reduces the energy required by the moving coil to produce the same acoustic effect, as the magnetic material is already in a magnetized state ready to interact with the moving coil's magnetic field.
2Object-generated harmful factors
If conventional systems apply time varying signals to both stationary and moving coils, then acoustic output is achieved, but acoustic distortion increases
Solution Approach 1:
The patent employs feedback by detecting the current through the stationary coil and using this information to control the signal applied to the moving coil. The controller generates a voltage output for the moving coil that is inversely proportional to the magnetic flux in the air gap, which is determined based on the stationary coil current. This feedback mechanism compensates for nonlinearities and distortion, ensuring accurate reproduction of the input audio signal.
Solution Approach 2:
The system dynamically changes parameters by adjusting the voltage output for the moving coil based on the detected stationary coil current. The controller modifies the moving coil signal in real-time according to the magnetic flux conditions in the air gap, optimizing the acoustic output and minimizing distortion across different operating conditions.
3Device complexity
If voltage source amplifiers are used in automotive applications, then system simplicity is maintained, but protection and diagnostics for electronic components are insufficient
Solution Approach 1:
The controller performs self-service by continuously monitoring the stationary coil current and using this information to protect the electronic components. The system automatically adjusts operating parameters and can detect fault conditions through the current measurements, providing built-in diagnostics and protection without requiring additional complex monitoring hardware.
Solution Approach 2:
The stationary coil current detection serves multiple functions: it determines the magnetic flux for controlling the moving coil signal, provides feedback for distortion compensation, and enables protection and diagnostics for electronic components. This multi-functionality maintains system simplicity while enhancing reliability and component protection.
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 enhances efficiency, reduces power consumption, minimizes acoustic distortion, and provides effective protection and diagnostics for automotive applications, balancing long-term power losses between stationary and moving coils for optimal performance.
Implementation Method 1
a stationary coil positioned within a driver of the acoustic transducer and a controller configured to provide a stationary coil signal to the stationary coil based on the first reference signal and to measure a current through the stationary coil after providing the stationary coil signal to the stationary coil
Implementation Method 2
generate a first output indicative of the current through the stationary coil and to determine a magnetic flux in an air gap of magnetic material based on the first output
Implementation Method 3
generate a voltage output for a moving coil that is inversely proportional to the magnetic flux in the air gap. The voltage output provides an undistorted output that corresponds to the input audio signal
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
An acoustic transducer includes a controller configured to receive an input audio signal and to generate a first reference signal indicative of an envelope of the input audio signal. The controller is further configured to provide a stationary coil signal to a stationary coil of an acoustic transducer based on the first reference signal and to measure a current through the stationary coil after providing the stationary coil signal to the stationary coil. The controller is further configured to generate a first output indicative of the current through the stationary coil and to determine a magnetic flux in an air gap of magnetic material based on the first output. The controller is further configured to generate a voltage output for a moving coil that is inversely proportional to the magnetic flux in the air gap. The voltage output provides an undistorted output that corresponds to the input audio signal.