A Provocative Rant About Planar Magnetic Technology

Planar Magnetic Technology for Headphones

A handful of HiFi audio companies are trying to revive the planar magnetic technology. These companies make headphones with planar drivers that are based on the past that produce a a rich, planar closed back headphones full-bodied sound signature.

This paper examines the intrinsic characteristics of a planar magnetic device by looking at winding conduction losses leakage inductance, and winding capacitance. A method is also suggested to reduce these parasitic elements.

Low vertical height or low profile

As compared to traditional wire-wound magnets Planar magnetic technology has less profile and better efficiency. It also minimizes leakage capacitance and parasitic capacitance. This method also allows for the use of a smaller-sized core, which decreases the overall cost of the device. It also does not require the magnets to be clamped. This makes it ideal for power electronics devices.

Planar magnetic technology has the advantage of being lighter and smaller than traditional headphones. It can also operate an increased frequency range without distortion. This is due to the diaphragm, which is flat, used in these devices is usually constructed from a thin layer with a conductor trace. The film is able to react quickly to audio signals, and can produce high pressure levels.

The sound produced by these devices will be more acoustic and more precise. Many audiophiles prefer it, especially those who prefer listening to music at home or in the office. It is important to keep in mind, however, that a planar magnetic driver requires an amplifier that is powered and a digital audio converter (DAC) to work effectively.

The resulting sound is much more natural and precise than that of dynamic drivers. Planar magnetic drivers are also able to respond faster to changes in the audio signal, which is why they are the perfect choice for listening to fast music.

Despite their advantages however, planar magnet drivers do have some drawbacks. One is their high price that can be attributed to the large amount of magnetic material that is required for their operation. Their weight and size can also be a problem, especially when they are being used as portable devices.

Wide band gap (WBG) devices

Wide band gap (WBG) semiconductors are a type of material which have higher electrical properties than standard silicon-based devices. They can withstand higher current densities, higher voltages, and lower switching losses. This makes them ideal for optoelectronics and power electronics applications. Wide band gap semiconductors, including gallium nitride and silicon carbide, can provide significant improvements in performance and size. They are also more environmentally sustainable than conventional silicon-based products. These advantages make them appealing to aerospace and satellite manufacturers.

Planar magnetic drivers work using the same fundamental principles as dynamic drivers, with an electrical conductor moving between fixed magnets when audio signals are transmitted through them. However, instead of a coil that is attached to a conical diaphragm planar magnetic drivers use conductors in a flat array connected to, or embedded in, a film-like diaphragm which can be made thin. Conductors function as coils that are placed directly on the diaphragm and are positioned between two magnets, creating the aforementioned push/pull interaction that causes the diaphragm to move.

This technology produces distortion-free music and provides a unique pleasant sound. The driver moves in a uniform manner and swiftly because of the equal distribution of magnetic force over the entire surface and absence of a coil in the diaphragm. This produces a detailed and accurate sound. The resulting sound is known as isodynamic, orthodynamic, or magnetically-incident.

However, because of their complex design and higher price point headphones with planar magnetic drivers are generally more expensive than those using other driver technologies. There are several good and affordable choices, such as the Rinko from Seeaudio or S12 Z12 by LETSHUOER which were released recently.

Power electronics

Planar magnetics are able to disperse heat more efficiently than traditional wire wound components. This allows them to handle greater power without undue stress or strain that is audible. This makes them perfect for use in headphones. In addition to their improved efficiency, planar magnetics also allow for greater power density. The technology is especially suitable for applications like fast charging of electric vehicles, battery management and military systems.

As opposed to dynamic driver headphones which make use of a diaphragm suspended by a voice coil planar magnetic drivers work on a much different principle. A flat array of conductors sits directly on the diaphragm and when an electromagnetic signal flows through the array, it triggers an interaction that pushes and pulls with the magnets on both sides of the diaphragm. This generates sound waves that move the diaphragm creating audio.

Planar magnetic devices are more efficient than conventional magnetics since they have a greater surface-to-volume ratio. This means they are able to disperse more heat, which allows them to operate at higher switching frequencies without exceeding their maximum temperature ratings. They have lower thermal sensitivities when compared to wire-wound devices. This allows them to be used in smaller power electronics circuits.

To optimize a planar boost inductor, designers should take into consideration a variety of factors, including the fundamental design, winding configuration, losses estimation, and thermal modeling. Ideal characteristics of an inductor include low winding capacitance, minimal leakage inductance, and easy integration into a PCB. It must also be able to handle high currents and be of a compact size.

In addition, the inductor needs to be compatible with a multilayer PCB using SMD or through-hole packages. The copper thickness should be sufficient to prevent thermal coupling and to limit eddy-currents between conductors.

Flexible circuit-based planar Winding

In planar magnetics, flex-circuit-based windings can be used to create an efficient resonator. They are made from a single-patterned dielectric film and an individual-patterned copper foil. The most popular choice is copper foil, which has superior electrical properties and is processed to permit termination features on both sides. The conductors in a flex circuit are joined with 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 planar headphones, a diaphragm sandwiched between two permanent magnets. The magnets vibrate in response to electrical signals generated by your audio device. These magnetic fields generate an audio wave that travels across the entire diaphragm's surface, creating a piston-like motion that prevents breakups and distortion.

One of the major advantages of planar headphones is their ability to reproduce a larger frequency range, specifically in the lower frequencies. The reason is that they have a larger surface area than traditional cone-shaped speakers, allowing them to move more air. They also reproduce bass sounds at a higher level of clarity and detail.

However they are costly to manufacture and require a powered amplifier and DAC to work effectively. They are also larger and heavier than traditional drivers, making them difficult to transport. In addition their low impedance demands an enormous amount of power to drive them which can quickly add up when you're listening to music at high volumes.

Stamped copper winding

The use of stamped copper windings with planar magnetic technology can improve the window utilization rate and reduce manufacturing costs. The method involves putting grooves in the coil body to hold the windings in a layer-accurate location. This method helps prevent deformations of the coil and improves tolerances. It also reduces the amount of scrap created during production and improves quality assurance. This type of planar coil is typically used in relay and contactor coils, ignition coils, and small transformers. It is also suitable for devices with wire thicknesses of up to 0.05 millimeters. The stamping process creates an even winding that has high current density. The windings will be precisely placed.

Planar magnetic headphones, unlike traditional dynamic drivers that use a voicecoil conductor in the diaphragm's thin surface, feature an array of conductors that are flat directly bonded to the thin diaphragm. When electronic signals are applied to these conductors, they vibrate, creating a pistonic motion that creates sound. In the end, planar magnetic headphones can produce higher-quality sound than other types of audio drivers.

In addition to reducing weight and cost in addition, this technology can also increase the bandwidth of planar closed back headphones magnetic transducers. This is crucial because it allows them to operate over a wider frequency range. It also reduces the power requirements of the driver.

This new technology does have some drawbacks. It isn't easy to design a thin-film diaphragm that can withstand the high temperatures required by this technology. However, companies such as Wisdom Audio have overcome this problem by creating an adhesive-free solution that can withstand temperatures up to 725degF (385degC). This allows them to produce audio of superior quality, without sacrificing durability and longevity.