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

Compute the wavelength of the light, Q. In Young's double slit experiment t...

Q. In Young's double slit experiment the distance between the slits is 1.9 mm. The distance between the slit and the screen is 1 m. If the bandwidth is 0.35 mm Compute the waveleng

Ratio of masses of proton and electron is, Ratio of masses of proton and el...

Ratio of masses of proton and electron is: (1) Infinite (2) 1.8x10 3     (3) 1.8         (4) None of these Ans: (2) 1.8x10 3

Calculate the transmit power required from the satellite, 1.  There are 40 ...

1.  There are 40 such microwave hops in tandem.  What is the end-to-end C/N of the link? 2.  Assume now that these 40 hops are replaced by a single satellite hop as shown below.

Illustrate properties of electromagnetic waves, Q. Illustrate what two prop...

Q. Illustrate what two properties of electromagnetic waves are used to attach info to radio signals? Answer:- By changing the amplitude of a radio wave you can encode info

Determine the self inductance of the coil, What do you mean by transformer ...

What do you mean by transformer ratio? A current of 2A is passed through a coil of 1000 turns to produce a flux of 0.5µwb. Determine the self inductance of the coil.

Define collisions, When two particles tend to each other, their motion alte...

When two particles tend to each other, their motion alters or their momentum modify because of their mutual interactions. This phenomenon is called as collision. During collision

MECHANICS, A LADDER OF LENGTH 4m weighing 300N is placed against vertical w...

A LADDER OF LENGTH 4m weighing 300N is placed against vertical wall . the coefficient of friction between the wall and the ladder is 0.3.The ladder in addition to its own weight ha

How to find gravitational potential energy ?, To work out the gravitational...

To work out the gravitational potential energy of an object the equation is: GPE = m x g x h Where: m = the mass of the object (kg) g = gravitational field strength (on earth tha

Describe the construction of optical fiber, Describe the construction of op...

Describe the construction of optical fiber. Explain the principle of propagation of light waves within a fiber. Define acceptance angle and acceptance.  How optical fibers can be u

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