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 spring force (fspring), Explain Spring Force (Fspring) Force ex...

Explain Spring Force (Fspring) Force exerted by a compressed or stretched spring upon any object that attached to it. An object that compresses or stretches a spring is always

Dteremine the Acceleration of the rocket , After being launched, a rocket a...

After being launched, a rocket attains a speed of 122 m/s before the fuel in the motor is completely used. If you suppose that the acceleration of the rocket is constant at 32.2 m/

Determine displacement current, Show that the displacement current flowing ...

Show that the displacement current flowing between the two plaes of the capacitor is similar to the conduction current utilized in charging the capacitor.

Explain the total magnetic flux in the ring, A coil of 600 turns is wound u...

A coil of 600 turns is wound uniformly on a ring of non-magnetic material. The ring has a uniform cross-sectional area of 200mm 2 and a mean circumference of 500mm. If the current

The size of nucleus is measured, The size of nucleus is measured in: (1...

The size of nucleus is measured in: (1)amu (2)Angstrom (3)Fermi (4)cm Ans: (3)Fermi

Who discovered proton, Who discovered Proton? In 1886 Eugen Goldstein d...

Who discovered Proton? In 1886 Eugen Goldstein discovered canal rays (also called as anode rays) and showed that they were positively charged particles (ions) formed from gases

Applications of superconductors: a 15 phases, An inter metallic compound ha...

An inter metallic compound having the chemical formula A 3 B, where A represents a transition element and a crystal structure in which the B atoms are located as the corners and in

Problems/force-mc-rotating-two-masses.tex, A block of mass m is tied to a c...

A block of mass m is tied to a cord of length L that is pivoted at the center of a frictionless table. A second block of mass m is tied to the ?rst block also on a cord of length L

Draw a labelled diagram of van de graff generator, An a.c. voltage E = E 0 ...

An a.c. voltage E = E 0 sin cot is applied across an inductor L. Get an expression for current I. Draw a labelled diagram of Van de Graff generator. Verify its principle of wor

Multimode - step-profile fibre, A multimode, step-profile fibre has a core ...

A multimode, step-profile fibre has a core radius of 50 microns, a core index of 1.52 and a cladding index of 1.50.  (a) If the fibre end-face is excited by a source with a wave

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