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

Optics, how does a magnifying glass work to produce a large or smaller imag...

how does a magnifying glass work to produce a large or smaller image?

Illustrate the electric field lines of a point charge q, The electric field...

The electric field E because of a point charge at any point near it is explained as where q is the test charge and F is the force acting on it. What is the physical significance of

What is equipotential surface, What is Equipotential Surface Equipoten...

What is Equipotential Surface Equipotential Surface - surface of constant potential.  No work is required in moving charges with such a surface. Electric fields are perpend

Fullerene structure and properties, FULLERENE: The fullerene is a cage l...

FULLERENE: The fullerene is a cage like hollow molecules composed of hexagonal and pentagonal groups of atoms, and especially those formed from carbon, that constitute the third

Find the ratio of radii of the two wires, Q. Two wires of same material and...

Q. Two wires of same material and same length have resistances 5 and 10 respectively. Find the ratio of radii of the two wires. R = ρl / A = ρl / πr 2  R 1 = ρl / A = ρl

What is the average velocity of the balloon, The position-time graph for a ...

The position-time graph for a hot-air balloon that is in flight is shown in the accompanying figure.   a) What is the average velocity of the balloon? b) What is the

The nature of anode rays depends upon, The nature of anode rays depends upo...

The nature of anode rays depends upon: (1) Nature of electrode (2) Nature of residual gas (3) Nature of discharge tube (4) All the above Ans:(2) Nature of residual

Explain the meaning of diffraction, Explain the meaning of Diffraction ...

Explain the meaning of Diffraction The spreading of a wave around a corner or through a slit of width b, which is about an order of magnitude of the size of the wavelength, is

Determine the Effect of air resistance, An object in free fall has an accel...

An object in free fall has an acceleration of 9.80 m/s 2 assuming that there is no air resistance. What is the speed of an object dropped from the top of a tall cliff 3.50 s a

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