Multi-Layer Coil for Smart Equipment
Key Characteristics
There is no magnetic core, hence no saturation problem.
This coil has a high Q factor, especially at high frequencies.
It also offers good linearity.
Signal distortion is held to a minimum.
The value of inductance is stable and does not change with temperature
Such coils may be used in radio frequency and precision work.
High Stability Multi-Layer Coil Unit
Air Core Coil for Precision Control
| Item |
Description |
| Winding Wire |
Enameled copper wire |
| Wire Diameter |
Custom (AWG options available) |
| Winding Type |
Multi-layer round or sectional winding |
| Core Material |
Air (non-magnetic) |
| Bobbin |
Optional plastic or ceramic |
| Encapsulation |
Optional varnish, epoxy, or coating |
| Mounting |
Through-hole / Custom |
Electrical Specifications (Typical)
| Parameter |
Description |
| Inductance Range |
0.1 µH – 100 µH (customizable) |
| Inductance Tolerance |
±2%, ±5%, ±10% |
| DC Resistance (DCR) |
Depends on wire diameter and turns |
| Q Factor |
High Q, optimized for frequency range |
| Self-Resonant Frequency |
High, application dependent |
| Operating Frequency |
kHz to MHz range |
| Rated Current |
Custom per design |
| Insulation Resistance |
≥100 MΩ |
WL4520 Air Core Coil for Automation Equipment
The WL4520 Multi-Layer Air Core Coil is commonly used in modern automation equipment that demands high frequency response, signal control, and electromagnetic reliability. The use of an air core minimizes magnetic saturation and core losses, which are essential for high-speed switching circuits and electronic control systems that are typical in automated production lines.
🔧 Typical Automation Applications
Sensor Signal Processing Modules – Offers a stable inductance value for precise filtering and detection in proximity sensors.
Robotic Control Systems – Accommodates high-speed control circuits that demand rapid response from an electromagnetic component.
PLC and Control Boards – Utilized for RF communication, filtering circuits, and electronic timing modules.
Smart Conveyors & Sorting Systems – Improves signal stability for motor driver circuits and electronic switching circuits.
Industrial Testing Equipment – Appropriate for measurement modules that require minimal distortion in signal transmission.
⚡ Application Advantages
High frequency efficiency without core loss
Lightweight and compact for space-limited equipment
Stable performance for long operating life
Low electromagnetic interference influence
Rapid response for high-precision control circuits
In an automation application where reliability and signal accuracy are at a premium, the WL4520 air core coil is an excellent choice for designers requiring a reliable electromagnetic solution for modern industrial electronics and intelligent machinery.
The Adv. and Disadvantage of Multi-Layer Air core coil
Advantages of an air core coil:
Its inductance is unaffected by the current it carries.
This contrasts with the situation with coils using ferromagnetic cores whose inductance tends to reach a peak at moderate field strengths before dropping towards zero as saturation approaches. Sometimes non-linearity in the magnetization curve can be tolerated; for example in switching power supplies and in some switching topologies this is an advantage.
In circuits such as audio cross over filters in hi-fi speaker systems you must avoid distortion; then an air coil is a good choice. Most radio transmitters rely on air coils to prevent the production of harmonics.
Air coils are also free of the “iron losses” which a problem with ferromagnetic cores. As frequency is increased this advantage becomes progressively more important. You obtain better Q-factor, greater efficiency, greater power handling, and less distortion.
Lastly, air coils can be designed to perform at frequencies as high as 1 GHz. Most ferromagnetic cores tend to be rather lossy above 100 MHz.
And the “downside”:
Without a high permeability core you must have more and/or larger turns to achieve a given inductance value. More turns means larger coils, lower self-resonance due to higher interwinding capacitance and higher copper loss. At higher frequencies you generally don’t need high inductance, so this is then less of a problem.
Greater stray field radiation and pickup:
With the closed magnetic paths used in cored inductors radiation is much less serious. As the diameter increases towards a wavelength (lambda = c / f), loss due to electromagnetic radiation will become significant. You may be able to reduce this problem by enclosing the coil in a screen, or by mounting it at right angles to other coils it may be coupling with.
You may be using an air cored coil not because you require a circuit element with a specific inductance per se but because your coil is used as a proximity sensor, loop antenna, induction heater, Tesla coil, electromagnet, magnetometer head or deflection yoke etc. Then an external radiated field may be what you want.
FAQ Of Multi-Layer Air Core Coils
