Air-Core Inductor, Iron-Core Inductor, Ferrite-Core Inductor, Variable Inductor


An inductor is an electronic component that stores energy temporarily in its magnetic field. It's composed of two terminals and a conductor, which is usually copper wire. This can be wrapped around air or a core material, for example, iron.

magnetic core and a wire together give us an inductor

When the wire is coiled around a material instead of air, this can make the magnetic field stronger. If the current passing through the inductor changes, the stored energy is quickly released. This happens due to the magnetic field of the inductor collapsing due to the current change. 

One of the most important qualities that inductors have is their ability to protect circuits from sudden changes in current. They do this by resisting changes in the flow of electricity, and the circuit is protected from shortages due to current spikes and fluctuations. This ability of an inductor is measured through the Inductance. More specifically, the inductance is the measure of the strength of the magnetic field for a measure of current passing through. To measure inductance, the Hennry (H) is used. One Henry is equivalent to one volt-second per ampere. Inductance can be affected by various factors, such as:

  • Material of the coil (copper, 
  • Material of the core (air, iron, ferrite, etc.)
  • Total area of the coil
  • Number of times the coil is wound
  • Material permeability

In practical applications, inductance is a crucial parameter as it affects how an inductor behaves in a circuit. It influences the inductor's ability to resist changes in current and voltage and plays a significant role in determining the behavior of electrical systems involving inductors, such as filters, transformers, and motors.


The following is a table of inductors that use specialty chemicals, adhesives, and plastics:

Type of Inductor Core Material Advantages Applications
Air Core Inductor Non-conductive medium, like air or plastic No iron losses due to increased frequency High frequency
Iron Core Inductor Iron Core High inductance Power
Ferrite Core Inductor Ferrite Core Good magnetic and high-frequency properties Radio Frequency Circuits
Variable Inductor Ferrite core in a threaded structure Allows inductance to be adjusted based on the core position Power, radio frequency circuits, research and development
Toroidal Inductor Ferrite, Iron, or metal core Closed loop shape allows wide frequency range, high inductance, and low EMI (electromagnetic interference) Power, radio, audio, and medical equipment (low EMI required)


Epoxy Coating Powders for Inductors

GCP18-05: Halogen-Free Epoxy Coating Powder for Passive Electronic Components

LINQSOL™ GCP1805 is an insulating epoxy coating powder for capacitors, varistors, and other passive components.  It was designed specifically as a halogen-free version of DK18-05 with similar technical specifications, just without containing any of the halogens. It can be applied through a fluidized bed with temperatures as low as 105°C. Its excellent curing conditions make the epoxy coating powder also very suitable for tantalum capacitors and other temperature-sensitive devices.

LINQSOL™ GCP1805 epoxy coating powders are laser markable and are rated with a UL 94 V-0 flammability and RTI rating of 130°C.

powder coated toroidal core