Voice Coil Array Speaker for Low Inductance and Passive Cooling
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Solution Overview
Problem
Existing voice coil speakers face challenges in minimizing permanent magnet material, coil inductance, operating at high efficiency, and providing effective cooling, which are crucial for improved frequency bandwidth and power handling.
Innovation Solution
A voice coil array speaker design featuring a speaker assembly with a heat-conducting front plate and thermal bridges, using high thermal conductivity materials for the coil former and incorporating an array of laterally and vertically polarized magnets with flux concentrators to enhance magnetic flux density and passive cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If permanent magnet material is reduced, then cost and weight are improved, but magnetic flux density decreases
Solution Approach 1:
The magnet assembly is segmented into multiple individually polarized magnets arranged in an array, allowing optimized magnetic flux distribution across multiple coil elements while using less total magnet material compared to a single large magnet
Solution Approach 2:
Different regions of the magnet assembly have different polarization directions (lateral and vertical), creating locally optimized magnetic flux patterns that match the coil arrangement and improve overall efficiency
2Productivity
If coil inductance is minimized, then frequency bandwidth is improved, but magnetic circuit reluctance increases
Solution Approach 1:
Flux concentrators are introduced as intermediary components between the magnets and coils to guide and concentrate magnetic flux, reducing the reluctance of the magnetic circuit while maintaining low inductance characteristics
Solution Approach 2:
The magnetic circuit parameters are optimized by changing the arrangement and polarization of multiple magnets, creating a configuration that achieves low inductance without excessive reluctance
3Temperature
If active cooling methods are used, then heat dissipation is improved, but device complexity and cost increase
Solution Approach 1:
The coil formers serve dual functions as both structural support and heat sinks, passively dissipating heat from the coils through their thermal mass and conductivity without requiring active cooling components
Solution Approach 2:
The cooling function is extracted from the coil formers by adding separate thermal bridges that conduct heat away from the coil assembly to the magnet assembly, which acts as a heat sink
4Temperature
If thermal bridges are added for cooling, then heat conduction is improved, but device complexity increases
Solution Approach 1:
The thermal bridges are merged with the existing magnet assembly structure, using the magnet housing or mounting structure as part of the thermal conduction path, thereby adding cooling functionality without significant additional components
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
The design achieves reduced magnet material usage, lower inductance, higher efficiency, and effective passive cooling, enabling operation at higher power levels and improved frequency response.
Implementation Method 1
thermal bridges configured to conduct heat from the heat conducting front plate to the speaker frame
Implementation Method 2
The interaction between the current passing through the voice coil and the magnetic field causes the voice coil to oscillate in accordance with the electrical current and drive the diaphragm to produce sound
Implementation Method 3
an array of laterally and vertically polarized magnets in contact with flux concentrators
Data Source
AI summary
Example embodiments provide a voice coil array speaker comprising a speaker assembly, a coil assembly, and a magnet assembly. The speaker assembly may comprise a speaker frame, a stationary base plate, a diaphragm configured to be capable of axial movement, a heat conducting front plate connected to the diaphragm, and thermal bridges configured to conduct heat from the heat conducting front plate to the speaker frame. The coil assembly may be connected to the heat conducting front plate, the coil assembly may comprise an array of coils wound around coil formers. The magnet assembly may be attached to the stationary base plate, the magnet assembly may comprise an array of laterally and vertically polarized magnets in contact with flux concentrators. The array of coils may be connected such that the direction of current flow alternates between clockwise and counterclockwise moving laterally across the array.