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 bohr's model, Bohr given a model for hydrogen molecule which is als...

Bohr given a model for hydrogen molecule which is also applicable for some lighter atoms in which a one electron revolves around a stationary nucleus of positive charge Ze (known a

Determine the self inductance of the primary coil, In the device shown in F...

In the device shown in Figure, when the current in the primary coil of 1000 turns increases linearly from 1A to 6A in 200ms, an e.m.f. of 15V is induced into the secondary coil of

Calculate the wavelength of the light used, Q. A Plano-convex lens of radiu...

Q. A Plano-convex lens of radius 3 m is placed on a flat glass plate and is illuminated by monochromatic light. The radius of the 8th dark ring is 3.6 mm. Calculate the wavelength

Capacitors in parallel, Capacitors in parallel: Three capacitors are co...

Capacitors in parallel: Three capacitors are connected in parallel. If on closing the switch S a current I flows in the circuit, then from Kirchoff's first law:

Luxon, luxon: A particle which solely travels at c (the speed of light...

luxon: A particle which solely travels at c (the speed of light in vacuum). All of the luxons have a rest mass of zero exactly. Though they are massless, luxons carry momentum

Is there any way to improve side- emitting viewing, Is there any way to imp...

Is there any way to improve side- emitting viewing? A side emitting light guide is viewed optimally while the contrast among the optic and background is maximized. When the lig

Resolution of forces, a small block of weight 10 Ib is placed on an incline...

a small block of weight 10 Ib is placed on an inclined plane which makes an angle of 30 degree with the horizon. resolve the gravitational force.

Explain linear circuit, Linear circuit :- It can be described as one, wh...

Linear circuit :- It can be described as one, whose parameters are constant i.e. they do not change with voltage or current.

Is electric potential is a function of x only, What does it signify to say ...

What does it signify to say that the electric potential is a function of x only? More exclusively what does the equipotential diagram (in 3-dimensional space) look like in the case

Determine fluid density and viscosity, It is known that the pressure develo...

It is known that the pressure developed by a centrifugal pump, Δp, is a function of the diameter D of the impeller, the speed of rotation n, the discharge Q, and the fluid density

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