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

Dimensional analysis, if the universal gravitational force depends on the p...

if the universal gravitational force depends on the product of the masses and depends on the distance between the masses ,find an expression for the universal force, and the unit f

What are magnetic fields, What are Magnetic Fields? Like electric and g...

What are Magnetic Fields? Like electric and gravitational fields, a magnetic field is a construct which helps you determine the force on a pole due to a magnet generating the f

Explain the normal force - balanced forces, Explain the Friction Fricti...

Explain the Friction Friction is a force that works against all motion. It slows everything down and it is the reason that the motion we are most familiar with always seems to

What are the characteristics of dead stars, What are the characteristics of...

What are the characteristics of dead stars? Dead stars are generally cold balls of material in empty space. A teaspoonful of white dwarf matter would weigh as more as an Ele

Strength of material, a 10 m radius of thin spherical tank is to be used to...

a 10 m radius of thin spherical tank is to be used to store gas if the wall thickness of the tank is 10 mm and the 125 mpa the maximum possible gas pressure neglecting the radial s

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.

Define curie-weiss law, It states that at temperatures Curie temperature th...

It states that at temperatures Curie temperature the magnetic susceptibility of ferromagnetic materials is inversely proportional to (T - Tc) i.e

Magnifying glass, Magnifying Glass: A biconvex lens of short focal leng...

Magnifying Glass: A biconvex lens of short focal length and low power which forms a virtual and magnified image of an object placed with its focal length is known as magnifying

What are the merits of typical ultrasonic flaw detector, What are the merit...

What are the merits of typical ultrasonic flaw detector? Merits of typical ultrasonic flaw detector: a. Particularly one side of the specimen is needed for the study. b.

Aameter, aameter - construction and working

aameter - construction and working

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