Electrostatic Shielding

Electrostatic shielding occurs when a faraday cage operates to block the impacts of an electric field. The cage blocks the impacts of an external field or internal field on the outside content. Michael Faraday took a high voltage generator and made a large wired cage supported on insulators. When the cage was charged with an induction machine, Faraday observed no deflection in electroscopes. Electrostatic shielding has been a method of protecting or shielding a particular space or region or any other sensitive instrument from the effect of an external field that has been produced by an electric charge.

The Faraday cage effect is well known whereby a metal screen or wire mesh serves as a barrier that blocks electromagnetic waves and electric fields. Faraday used a twelve-foot mesh cube for his experiment which have been used by physicist and engineers as metal shielding to isolate systems and circuits (James, 2010). To protect themselves from being electrocuted or killed by electric shock, the mesh wire cube is used to protect an object from high electric fields through a hollow conductor.

Faraday found out that when the metal cage that acts like an electric conductor is charged, the charges are only present on the surface with no impact on the interior. The electrostatic shielding has a cage-like appearance that is made of chains like fences and final metal mesh that vary in designs and sizes (Ting & Xi, 2017). Ideally, the cage can hold an electrostatic charge as well as the electromagnetic field in a manner that gets distributed on the exterior material. The charge distribution on the exterior material happens in such a manner that the charges will cancel with the charges in the interior.

Electrostatic shielding guard assemblies as well as components from failure and damage resulting fromoutside electrostatic fields(Tripathi, Wilson, and Youngquist, 2008). The extentof the demanded guarding depends on the level of an electric field that leads to damage. The electrostatic effects were barred through an extremely conductive field that acted as an electrostatic shield since the early stage of electricity. Considerably, the basic ideologies of electrostatic shielding can easily be obtained from electrostatic knowledge.

The objective of electrostatic shielding is to create a space where the electric field is free of what occurs in the externalregion. The effectiveness of electrostatic shielding varies on the construction of the cage. Variations on the conductivity of the various metals such as aluminum or copper influenced the function of the cage. For instance, the Faraday shield offers a copper electrostatic shield between the secondary and primary windings. The shield is grounded and thus prevents noise and transients to the ground path instead of passing them through to the secondary winding. The size of the hole in the mesh or screen also affects the changes in the capabilities of the electrostatic shielding. However, the electrostatic shielding can be adjusted with regards to the wavelength and frequency of the electromagnetic radiation that needs to be excluded from the interior.

Electrostatic shielding facilitates lightning safety in cars and airplanes. The protective metal compartment of the plane or car acts as a Faraday cage that protects the passengers from external lightning electric charges. For instance, during a lightning thunderstorm, staying inside a car can be safe rather than staying under a tree or in an open ground. The metallic body of the car acts as an electrostatic shielding from lightening. The electric discharge goes through the body of the car where the electric field is zero (Êvo, & de Paula, 2020). Cars have a metallic body where no electric field or charge can pass through. The car acts like a faraday cage or a hollow conductor. Therefore, due to the electrostatic shielding phenomenon, the metallic body of the car protects from the impact of the external electric field. The electrostatic shielding is also utilized in wires carrying audio signals to protect them from external interference. They are also used on Magnetic Resonance Imagining (MRI) scan rooms to prevent the external radio frequency indicators from distorting any data that comes from the patient.

Electrostatic shielding is used for electronic devices. It is vital to guard different electronic devices from electromagnetic radiation. For instance, the coaxial cables that are utilized in televisions have a copper braided shield on the PVC jacket that acts as the Faraday cage(Raicevic et al.,2018). This protects the internal conductors from any RF leakage and external electronic noise. Microwave that has a metal shell that acts as a Faraday cage. Ideally, there is a need to cover an item that does not have to be heated with a conducting material. This is considered Faraday’s cage. The covering material has to be a conductor since conductors have the property that free charges can freely move without great resistance inside.

The protective gears for linemen and electricians have electrostatic shielding which is used in hazardous settings. They are a type of Faraday cage that is used to protect the workers from being electrocuted while operating near high voltage power lines.  In the protective gears, the distribution of charges in the external environment occurs in such a manner that the charges will cancel with the interior.

In summation, electrostatic shielding entails ensuring a region is free from any electric field. A Faraday cage is used to block the impacts of an electric field within a certain space. The cage can be used to block impacts of external electric fields on its internal contents or the effects of an internal setting on the external contents. Electrostatic shielding has been used in electronic equipment, for lightening safety, MRI, and protective gears. Electrostatic shielding has been used in various fields to prevent electric charges and electrocution.

References

Êvo, M. T. A., & de Paula, H. (2020). Electrostatic shielding for bearings discharge currents attenuation: analysis of its effectiveness, losses, and impact on the motor performance–a study for design guidelines. IET Electric Power Applications, 14(6), 1050-1059.

James, F. A. (2010). Michael Faraday: a very short introduction (Vol. 253). Oxford University Press.

Raicevic, N. B., Aleksic, S. R., Hederic, Ž., Barukcic, M., & Iatcheva, I. (2018). Optimal selection of coaxial ring systems in environmental electrostatic shielding. COMPEL-The international journal for computation and mathematics in electrical and electronic engineering.

Ting, H., & Xi, D. (2017, April). Analysis of Electromagnetic Shielding Stability in electronics shelter. In 2017 7th International Conference on Manufacturing Science and Engineering (ICMSE 2017) (pp. 301-306). Atlantis Press.

Tripathi, R. K., Wilson, J. W., & Youngquist, R. C. (2008). Electrostatic space radiation shielding. Advances in Space Research, 42(6), 1043-1049.