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

Special resistor materials: the lead alloy, The lead alloy: Most of the so...

The lead alloy: Most of the soldering in the electronic industry is carried out using tin lead alloy. Pure lead metals at 327 0 C, whereas tin melts at 232 0 C and the mixture of

Illustrate what is the direction of null vector, Q. Illustrate what is the ...

Q. Illustrate what is the direction of null vector? Answer:- There are two probable answers to this 1) It contain no direction 2) It points in every direction Ans

Find the gain in system, For the system shown below the gain, G, of block A...

For the system shown below the gain, G, of block A is variable and can be set as low as 100 and as high as 500. The only problem with block A is that its gain fluctuates with high

Two forces p and 2p act on the particle, Two forces P & 2P act on the parti...

Two forces P & 2P act on the particle if the first is doubled & the second enhanced by 20N.The direction of the resultant remains unchanged. What is the value of P.

Newtons law of motion, a dock worker loading crates on a ship finds that a ...

a dock worker loading crates on a ship finds that a 24kg crate, intially at rest requires a 65N horizontal force to set it in motion.However,after the crate is in motion, a horizon

Water, Is there any experiment to tell that water can move from lower conce...

Is there any experiment to tell that water can move from lower concentration to higher Which means flows back to mountain without reversing time Could water flow upward by itself w

What are the safety terms to be inspected on wiring, What are the safety te...

What are the safety terms to be inspected on wiring? Ans: Safety terms to be checked on wiring are securing of wiring through cleats with trough provision of correct size of

What is the average acceleration of the car, A car travelling at 21 m/s mis...

A car travelling at 21 m/s misses the turnoff on the road and collides into the safety guard rail. The car comes to a totally stop in 0.55 s. a. What is the average accel

Visualize the effects of moving sources, Draw a picture of a moving source ...

Draw a picture of a moving source and the waves surrounding it according to what you observed in this experiment. How does the spacing of the wave-fronts in front of the source com

What are one dimensional wave , Energy is transferred in a one direction on...

Energy is transferred in a one direction only. Example : Wave propagating in a stretched string.

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