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

Measuring field strength of permanent magnets, I want to measure H, not B T...

I want to measure H, not B The magnets in question are permanent magnets (large Neo or SmCo magnets), not coils =====================....Steel ____........................____ |.

State gauss theorem in electrostatics, State Gauss' theorem in electrostati...

State Gauss' theorem in electrostatics. Using this theorem, derive the expression for the electric field intensity at any point outside a uniformly charged thin spherical shell.

Buoyancy, Why do dead bodies float in water ?

Why do dead bodies float in water ?

What is the slit separation, Light with a wavelength of 454.5 nm passes by ...

Light with a wavelength of 454.5 nm passes by two slits that are 95.2 cm from a screen. The distance among the centers of the central band and the first-order band is 15.2 mm.

Help, Azelastine hydrochloride is an antihistamine nasal spray. A standard ...

Azelastine hydrochloride is an antihistamine nasal spray. A standard size container holds one fluid ounce (oz.) of the liquid. You are searching for this medication in a European d

Determine apparent weight, During a space launch, an astronaut typically un...

During a space launch, an astronaut typically undergoes an acceleration of 3 gs, which means he experiences an acceleration that is three times that of gravity alone. What wou

Brewsters law, Brewster's law (D. Brewster) The extent of the polariza...

Brewster's law (D. Brewster) The extent of the polarization of light reflected through a transparent surface is maximum while the reflected ray is at right angles to the refra

Whta is mach number , Mach number is the ratio of velocity of source to the...

Mach number is the ratio of velocity of source to the velocity of sound.        Mach Number = Velocity of Source / Velocity of Sound  .

Top of a tower a stone, From top of a tower a stone is thrown up and it rea...

From top of a tower a stone is thrown up and it reaches the ground in time t1. A second stone is thrown down with the same speed and it reaches the ground in t2. A third stone is r

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