Understanding Dielectrics

by | Mar 8, 2023

Dielectrics, what exactly are they?

Dielectrics are defined as a type of insulation that exists among a pair of conductors and permits the polarizing of a charge, which is commonly referred to as electrostatic repulsing & attracting.

A dielectric is found in the middle of a center conductor as well as the external conductor within a coaxial cable. In the specific case of a twisted pair type of cable, it is not only the insulation found among the conductors but air or any insulating material that encompasses a conductor.

Terminology utilized at the moment of speaking about dielectrics:

  • Dielectric Breakdown – In the instance where a dielectric is changed and subsequently turns conductive. This typically occurs at the moment where high amounts of voltage are used and insulation does not function as needed.
  • Dielectric Constant – In the instance where the dielectric substance has the capacity of retaining electrostatic energy at the moment of utilizing voltage. This term can frequently be referred to as relative permittivity.
  • Dielectric Strength – In the instance where the voltage quantity an insulation is capable of withstanding prior to deteriorating. This is a desirable characteristic most engineers focus on since it demonstrates the resilience of a dielectric.
  • Dielectric Loss – In the instance where there is a diminishment of power due to the friction of a dielectric, which is brought by the flowing of molecules against the flow of an electric field. The diminishment of power is considered an undesirable characteristic.
  • Dielectric Absorption – In the instance where there is an accumulation of electric charges at the specific moment of contact between a dielectric and the electric field. This is a problematic characteristic since a quality dielectric obstructs electron movement.

Despite the fact that the words, ‘dielectric’ as well as ‘insulation’ are frequently exchanged for one another, ‘insulation’ normally refers to a substance with a lower capacity of conduction. On the other hand, the term ‘dielectric’ explicitly makes reference to insulating substances having strong polarizing propensities. The characteristics that make up a dielectric are crucial at the moment of selecting cables as they can be the deciding factors that will help or destroy the application. While selecting the ideal cable for your particular requirements, be aware of considering the mentioned dielectric characteristics.