Electrodynamic Transducer Driving Force Model Calibration
Solution Overview
Problem
Existing models of electrodynamic acoustic transducers often use a mean or best fit driving force function that does not accurately represent the actual driving force function of a particular transducer, leading to malfunction, distortion, and potential damage.
Innovation Solution
A method to determine an individual driving force function by applying input signals to both a real and a modeled electrodynamic acoustic transducer, calculating electromotive forces, shifting the modeled function to match the real transducer's forces, and updating the model with a scaling factor to ensure accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a mean or best fit driving force function is used to model the electrodynamic acoustic transducer, then the model can be simplified and easier to compute, but the accuracy of the model deteriorates leading to malfunction and distortion
Solution Approach 1:
The patent creates a digital copy of the actual driving force function by measuring electromotive forces from the real transducer and using those measurements to generate an accurate individual driving force function, replacing the inaccurate mean/best fit function. This copying approach allows the model to reflect the specific transducer's actual characteristics without requiring complex physical modifications.
Solution Approach 2:
The patent implements feedback by measuring the actual electromotive forces from the real transducer during operation and using these measurements to update and refine the modeled driving force function. This closed-loop approach continuously improves model accuracy by comparing actual performance with predicted performance and adjusting the model accordingly.
2Measurement precision
If an individual driving force function is determined through measurement and modeling, then the model accuracy improves, but the device complexity increases
Solution Approach 1:
The patent replaces complex physical measurement and adjustment procedures with computational methods. Instead of physically modifying the transducer or using complex measurement apparatus, the system uses electronic circuits and algorithms to measure electromotive forces and calculate the individual driving force function, simplifying the overall process while maintaining high accuracy.
Solution Approach 2:
The patent changes the approach from using fixed mean/best fit parameters to dynamically determining individual parameters specific to each transducer. By measuring actual electromotive forces and calculating unique driving force functions for each transducer, the system adapts parameters to match actual performance, improving accuracy without requiring overly complex physical modifications.
3Ease of operation
If the modeled driving force function is used without adjustment, then the system operation remains simple, but audio output distortion occurs and damage may result
Solution Approach 1:
The patent performs preliminary action by determining the accurate individual driving force function before the transducer is put into service. By pre-calculating and storing the correct driving force function specific to each transducer, the system ensures reliable operation from the start without requiring complex real-time adjustments or modifications during operation.
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 improves the accuracy of the model, reducing audio output distortions and ensuring the transducer operates closer to its intended performance, thereby preventing damage.
Implementation Method 1
a coil arrangement with at least two coils attached to the membrane, a magnet system being designed to generate a magnetic field transverse to a longitudinal direction of a wound wire of the coil arrangement
Implementation Method 2
calculating a graph of a first electromotive force for a first voice coil of the voice coils and a second electromotive force for a second voice coil of the voice coils of the real electrodynamic acoustic transducer
Data Source
AI summary
Method and electronic circuit for determining a scaling factor k for a driving force function of a model of an electrodynamic acoustic transducer having at least two voice coils. Input signal fed into the transducer and it's model cause electromotive forces. A shift for the driving force function is determined on the base of the ratios between the real electromotive forces and the modeled electromotive forces. Finally, the scaling factor k is determined on the basis of a deviation between the real electromotive forces and the modeled electromotive forces at time points where the real electromotive forces and the modeled electromotive forces each are equal. The invention moreover relates to an electronic circuit for performing the above steps, and to a transducer system with the electronic circuit and a connected transducer.