What Is Fixed Inductors And How Do They Work?

In the intricate world of electronics, inductors play a crucial role as fundamental components.

Among the various types of inductors available, fixed inductors have established a niche for themselves due to their reliable performance and wide-ranging applications.

Fixed inductors, as the name suggests, have a fixed value of inductance and are essential building blocks in various electronic devices and systems.

This article delves into the world of fixed inductors, discussing their types based on physical configurations – vertical sealed and horizontal sealed – along with a detailed analysis of their respective characteristics, including inductance ranges, rated working currents, and error ranges.

Additionally, we explore the broad applications of fixed inductors in different sectors like networks, telecommunications, computers, AC power supplies, and peripheral equipment.

We’ll also touch upon the increasing demand for fixed inductors in the low inductance range, a trend driven by the miniaturization of equipment and progress in digitization.

Join us as we navigate through the fascinating world of fixed inductors, unraveling their complexities and highlighting their indispensable role in modern electronics.

What is a Fixed Inductor?

A fixed inductor is a type of inductor whose inductance, the property to resist changes in electric current, remains constant.

They are manufactured by winding a wire, which could be layered in multiple configurations, around a magnetic core.

These configurations include single or multiple layers and may be in the form of honeycomb or a magnetic core.

Main Functions of Fixed Inductors

Fixed inductors perform several important functions in electronic circuits.

They form a resonant circuit with other electronic components, utilizing the characteristic of inductors to “pass direct current and resist alternating current”.

Below are the main functionalities of fixed inductors:

Filtering: Inductors can filter out specific frequency bands in signals to suppress and prevent interference, helping to ensure smooth and regular signal waveforms and to reduce signal noise.

Oscillation: In an oscillation circuit, an inductor is combined with a capacitor to form a circuit where the size and direction of current change periodically, producing an oscillating current.

Delay: An inductor can delay rapid changes in current, preventing circuit components from malfunctioning.

Notch: An inductor can minimize the impact of periodic voltage disturbances, which occur when the AC input current switches from one phase to another under normal working conditions of power electronic devices.

Types of Fixed Inductors

Fixed inductors can primarily be categorized into two types based on their physical structure: vertical sealed and horizontal sealed.

However, it’s crucial to understand the implications of these physical configurations in relation to their inductance ranges, rated working currents, and error ranges.

Vertical Sealed Inductors: These inductors are designed to stand vertically on a circuit board, thereby maximizing board space, which is a crucial aspect in modern compact electronic devices.

Vertical sealed inductors are generally designed to provide a higher inductance range, as the vertical configuration allows for more space for the coil windings, leading to a higher degree of inductance.

However, these inductors may have a lower rated working current due to the thermal constraints that arise from the physical configuration.

The error range, which represents the variability of the inductor’s actual inductance compared to its rated inductance, tends to be narrower in well-designed vertical sealed inductors.

Horizontal Sealed Inductors: These inductors lie horizontally on the circuit board. This configuration typically has a lower inductance range due to fewer coil windings, but they may have a higher rated working current because the horizontal configuration allows for better heat dissipation.

The error range in horizontal sealed inductors can vary greatly based on the quality of the manufacturing process.

The horizontal configuration is typically used in applications where space is not as critical or when a higher current rating is required.

Expanded Applications of Fixed Inductors

Fixed inductors play a pivotal role in numerous applications across various sectors, including networks, telecommunications, computers, AC power supplies, and peripheral equipment.

In networks and telecommunications, fixed inductors are used in filter circuits to remove unwanted frequency components, improving signal integrity and performance. For instance, they are used in mobile devices and base stations to manage radio frequency signals.

In the computer industry, fixed inductors are an integral part of power supply units and are used in DC-DC conversion, noise filtering, and power factor correction circuits. They also play a vital role in the operation of motherboards and other peripheral devices by regulating power supply and ensuring stable performance.

In AC power supplies, fixed inductors are used in circuits to reduce high-frequency noise and improve power quality. They are also used in the construction of transformers in power supply circuits.

In peripheral equipment, such as printers, scanners, and external storage devices, fixed inductors are used in power regulation and noise suppression circuits.

Moreover, with technological advancements leading to the miniaturization of equipment and progress in digitization, the demand for fixed inductors has seen a shift towards the low inductance range.

As circuits get smaller, the size of the inductors needs to decrease, leading to a lower inductance value. Despite this, they remain equally crucial to the operation of these devices by offering the same functionalities in a much more compact size.

This trend aligns with the broader trend in electronics towards smaller, more efficient, and highly integrated devices.

ELJ-NA2R2JF is a fixed inductor manufactured by Panasonic Electronic Components. It is a chip inductor designed for use in high-frequency applications such as RF circuits and power supplies. The inductor has an inductance of 2.2 microhenries (μH) and a rated current of up to 500 milliamperes (mA). It has a compact size of 3.2 x 1.6mm, making it suitable for use in small electronic devices such as smartphones, tablets, and wearables. The ELJ-NA2R2JF also features a ferrite core that provides high magnetic permeability and excellent energy storage efficiency.

Considerations When Working with Fixed Inductors

While using fixed inductors, it is important to keep several considerations in mind.

Firstly, the temperature must remain within the operating range to prevent changes in inductance due to temperature rise.

Attention should be paid to positioning adjacent inductors at a distance from each other or at right angles to reduce mutual induction.

You should also note that there can be gap capacitance between the windings of each layer of the inductor, which could lead to high-frequency signal bypass and reduce the actual filtering effect.

Conclusion

Fixed inductors are crucial components in many electronic circuits, playing a critical role in filtering, oscillation, delay, and notch functionalities.

Despite not having functional polarity and operating equally well in either direction, precautions related to temperature, positioning, and gap capacitance should be considered while working with them.

As technology continues to advance, the role of fixed inductors is expected to remain central to electronic devices and systems.