Planar Magnetic Technology for Headphones
A few HiFi audio companies are reviving the planar magnetic technology. These companies create headphones with traditional planar drivers that produce a a rich sound signature.
This paper focuses on the fundamental characteristics of a planar magnetic device by studying winding conduction losses as well as leakage inductance and winding capacitance. Additionally, a method to reduce the parasitic elements is proposed.
Low profile or low vertical height
In comparison to traditional wire-wound magnetics, planar magnetic technology offers lower profile and higher efficiency. It also reduces leakage and parasitic capacitance. This allows for the use of a smaller core used, which lowers the cost of the device. It also doesn't require that the magnets be clamped. This makes it ideal for power electronics devices.
Another advantage of planar magnetic technology is that it is lighter and more compact than traditional headphones. It also can handle higher frequencies with no distortion. This is due to the diaphragm, which is flat, that is used in these devices, which is usually made of a thin layer and includes a conductor trace on it. The film can react quickly to audio signals and produce high levels of sound pressure easily.
The audio generated by these devices will be richer and more detailed. This is the reason why it is preferred by many audiophiles, especially those who like listening to music at home or office. It is important to remember, however, that the planar magnetic driver needs an amplifier powered by electricity and a digital audio converter (DAC) to function properly.
The resultant sound is more natural and precise than that of dynamic drivers. Planar magnetic drivers are also capable of reacting to changes in audio signals much faster, making them ideal for listening to music that is fast.
Despite their benefits however, planar magnetic drivers come with many drawbacks. One is their high price that can be attributed to the massive amount of magnetic material required for them to operate. Their weight and size can be a hindrance, especially when they are being used as portable devices.
Wide band gap (WBG) devices
Wide band gap (WBG), semiconductors are materials that possess higher electrical properties than traditional silicon-based devices. They are able to handle higher current and voltage densities. They are therefore ideal for optoelectronics and power electronics applications. Wide band gap semiconductors like silicon carbide and gallium nitride can bring significant enhancements in terms of performance, size, and cost. They are also environmentally friendly than traditional silicon-based devices. These advantages make them attractive for companies that make satellites and aerospace.
Planar magnetic drivers are based on the same basic principles as dynamic drivers, using an electrical conductor that moves between fixed magnets when audio signals are transmitted through them. Instead of a coil that is attached to a conical diaphragm, planar magnetic drivers use an array of conductors that are flat attached to, or incorporated into a diaphragm-like film that is able to be made thin. The conductors are a set of coils' that sit on the diaphragm and sit directly between two magnets. This causes the push/pull phenomenon that creates the diaphragm's movement.
This technology creates distortion-free music reproduction and has a unique sound that many people find pleasing. The driver moves in a uniform manner and quickly due to the even distribution of magnetic force across the entire surface as well as the lack of a coil behind the diaphragm. This results in a clear and precise sound. The resulting sound is known as isodynamic, orthodynamic, or magnetically-incident.
Generally, headphones with planar magnetic drivers cost more than other technologies due to their complexity and price. However there are plenty of affordable, high-quality options like the Rinko by Seeaudio and S12 / Z12 by LETSHUOER that were recently released.
Power electronics
Planar magnetics can disperse heat more efficiently than wire wound components. This lets them handle more power without causing excessive strain or audible strain. This makes them ideal for applications like headphones. Planar magnetics are more efficient and also provide a greater power density. The technology is ideally designed for applications such as electric vehicle fast charging, battery management, and military systems.
Planar magnetic drivers work using a different model than dynamic driver headphones. Dynamic driver headphones use an acoustic diaphragm, which is suspended by the voice coil. When an electromagnetic signal is transmitted through the array and the magnets on either side of the diaphragm are pushed together and a push-pull effect is produced. This creates soundwaves that move the diaphragm and generate audio.
Because they have a greater surface-to volume ratio, planar magnetic devices are more effective than conventional magnetics. They are able to disperse heat more efficiently, which allows for higher switching frequencies while still maintaining their maximum temperature ratings. They have lower thermal sensitivities in comparison to wire-wound devices. planar magnetic iem allows them to be utilized in smaller power electronic circuits.
Designers need to consider a variety of aspects to optimize a planar booster. These include the core design winding configurations, winding configurations, losses estimation and thermal modeling. Ideally, the inductor should have a low leakage and winding capacitance, and be simple to integrate into the PCB. Additionally, it should be able to handle high currents and should be smaller size.
The inductor should also be compatible with multilayer PCBs with through-hole or SMD packages. The copper thickness should be sufficient to prevent thermal coupling and reduce eddy-currents between conductors.
Flexible circuit-based planar Winding
In planar magnetic technology the flex circuit-based windings are employed to make a high-efficiency inductor. They are made up of one-patterned conductor layers that are a flexible dielectric film and can be made using a variety of metal foils. Copper foil is a popular choice due to the fact that it has excellent electrical properties. It can also be processed to allow termination features on both the front and back. The conductors in a flex circuit are linked by thin lines that extend beyond the edges of the substrate, which provides the flexibility needed for tape automated bonding (TAB). Single-sided flex circuits can be found in a range of thicknesses and conductive coatings.
In a typical pair of headphones, a diaphragm is sandwiched between two permanent magnets. The magnets vibrate in response to electrical signals that are sent by your audio device. These magnetic fields generate a sound wave that travels across the entire surface of the diaphragm, creating a piston-like motion which prevents distortion and breakups.
Planar magnetic headphones can reproduce a wide range of frequencies, notably at lower frequencies. This is due to the fact that they can create a greater surface area than conventional cone drivers, allowing them to move more air. They can also reproduce bass sound at a higher level of clarity and details.
Planar magnetic headphones can be costly to produce and require a powered amplifier as well as a DAC for operation effectively. They are also larger and heavier than conventional drivers, making them difficult to transport or to fit into smaller spaces. Their low impedance requires much more power to drive, which could quickly increase when you listen to music at a high volume.
Stamped copper winding
Stamped copper windings can be used in planar magnetic technology to improve the window's utilization and decrease manufacturing costs. The method works by putting grooves on the body of the coil which ensure a precise layer of the windings. This technique prevents deformations in the coil and improves the tolerances. It also reduces the amount of scrap produced during production and enhances quality assurance. This type of planar coil is typically used in contactor coils and relay coils. It is also used in ignition coils and small transformers. It can also be used in devices that have a wire thickness of up to 0.05 mm. The stamping creates an uniform coil with a high current density. The windings will be precisely placed.
Planar magnetic headphones, in contrast to traditional dynamic drivers that use a voicecoil conductor behind the diaphragm's thin surface, feature a flat array of conductors directly connected to the diaphragm's thin. Conductors vibrate when electronic signals are applied. This creates the motion of pistons that produce sound. Planar magnetic headphones produce a higher-quality sound compared to other types of audio drivers.
In addition to reducing weight and costs, this technology has the potential to increase the frequency range of planar magnetic transducers. This is important because it permits them to operate in a larger frequency range. Furthermore, it lowers the overall power requirement of the driver.
However, there are negatives with this new technology. It can be difficult to design a thin-film diaphragm capable of withstanding the extreme temperatures required for this technology. However, companies such as Wisdom Audio have overcome this problem by creating an adhesive-free option that can withstand temperatures up to 725degF (385degC). This allows them to produce audio with superior quality without compromising durability and longevity.