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

air gap in between the parallel plates, How is that circuit wont be broken...

How is that circuit wont be broken even there is an air gap in between the parallel plates? Ans) In AC circuit capacitor offers resistance to current as aresistor would do in DC.

Formalism of synaptic plasticity, (a) Equation (3) may be viewed as a form...

(a) Equation (3) may be viewed as a formalism of synaptic plasticity - the synapse is able to change in strength in response to either use or disuse of it. We can observe the s

P-type semi conductor, What are the minority and majority charge carriers i...

What are the minority and majority charge carriers in a p-type semi conductor? How is a battery connected to a junction diode in a) forward and b) reverse-bias?

Explain phenomenon of scattering, Some phenomenon based on scattering: (...

Some phenomenon based on scattering: (i) Sky looks blue because of scattering. (ii)  At the starting time of sunrise or sunset sun looks reddish. (iii) Danger signals are

Coanda effect, Coanda effect The effect which indicates that a fluid t...

Coanda effect The effect which indicates that a fluid tends to flow along a surface, instead of flow through free space.

Explain armature core, Armature core:    It houses the armature conducto...

Armature core:    It houses the armature conductors or coils and causes them to rotate and as cuts the magnetic flux of field magnets. It also gives a path of very low reluctanc

Beauty criterion - dirac, Beauty criterion (Dirac) The idea that the m...

Beauty criterion (Dirac) The idea that the more aesthetically pleasant a theory is, the better it is. Of course this criterion does not stand up to the real test whether or no

Freely suspended charged particle, To free a charged a particle freely in a...

To free a charged a particle freely in air under the persuade of electric field its downward weight should be balanced by upward electric force for instance if a positive charge is

Flow in the coil as a result of the motion of the magnet, A bar magnet is o...

A bar magnet is overhanging north end up well above a vertical coil of wire. The bar magnet is released and as it falls down toward the coil it falls along a path that will take it

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