Spark suppression, Physics

Assignment Help:

Spark suppression:

If we consider a circuit with a large inductance, possibly one using a magnetic relay. At the instant the switch is opened, the current through the coil is changing at maximum rate, therefore the back emf induced in the coil is also at maximum.

This emf is applied to the air gap between the switch contacts and ionises the air, producing a spark which the burns the contacts. This increases their electrical resistance and radiates energy which may cause interference, therefore sparks must be suppressed. Good design of switch contacts can help, but connecting a capacitor in parallel with the switch is the best method of eliminating sparking.

When using a capacitor the energy released by the coil charges the capacitor instead of ionising air. When the switch is closed again the capacitor discharges.


Related Discussions:- Spark suppression

Explain line emission spectrum, (i) It having of dissimilar bright lines. ...

(i) It having of dissimilar bright lines. (ii) It is given by an excited source in atomic state. (iii)E.g. Spectrum of excited helium, mercury vapours sodium vapours or atomi

Effective mass, why effective mass are tensor quantities

why effective mass are tensor quantities

Reflection and refraction of waves, When rays are incident on a boundary am...

When rays are incident on a boundary among medium, a section of incident waves goes back into the initial medium whereas the remaining is sectionaly absorbed and sectionaly transmi

Explain the kinetic theory, Explain the Kinetic Theory Kinetic theory l...

Explain the Kinetic Theory Kinetic theory looks at how each of these steps adds more internal kinetic energy (jiggle energy) to the material. A solid is a framework of atoms an

Explain youngs double slit experiment, In case of Young's double slit exper...

In case of Young's double slit experiment if the yellow light is moved by red light then how the fringes are affected?

What are overtones and harmonics, What are "Overtones" and "Harmonics" ? Ho...

What are "Overtones" and "Harmonics" ? How are they build in an open pipe? Derive the mathematical equations for the frequencies of the harmonics produced in an open pipe.

Illustrate the value of collector current, Figure shows the transfer charac...

Figure shows the transfer characteristic for an n-p-n silicon transistor.When the base current is 2.5mA, Verify (a) the value of collector current, (b) the static value of

Dielectric material: plastics, Plastics are polymers, meaning they are made...

Plastics are polymers, meaning they are made up of molecules from many different elements. By utilizing different combinations, new polymers are made that can be manipulated from m

Logic gate, investigatory poject class 12

investigatory poject class 12

Explain corrosion, Explain corrosion This corrosion can happen either ...

Explain corrosion This corrosion can happen either when a conducting liquid is in contact with a metal or when two dissimilar metals /alloys are is partially immersed in a con

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd