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

Centrifugal force with a ring, Centrifugal force with a ring Secure an ...

Centrifugal force with a ring Secure an iron ring about 6 cm in diameter and Join it to the cord on the drill. Observe the effects.

Coulombs law, Coulomb's law (C. de Coulomb) The primary law for electr...

Coulomb's law (C. de Coulomb) The primary law for electrostatics is analogues to Newton's law of universal gravitation. This states that the force among two point charges is p

What are switches and fuses, What are Switches and Fuses? As men...

What are Switches and Fuses? As mentioned earlier, short circuits can be damaging to the voltage source. One way we have developed to protect equipment is to use fuses i

First harmonic- standing waves on a string, There are a variety of patterns...

There are a variety of patterns that could be generates through vibrations inside a string, slinky, or rope. Every pattern corresponds to vibrations that occur at a particular freq

What is the significance of poynting vector, Write down the differential fo...

Write down the differential form of Poynting theorem. What is the significance of Poynting vector?

How much should be the voltage of an x-ray tube, Q. How much should be the ...

Q. How much should be the voltage of an X-ray tube so that the electrons emitted from the cathode may give an X-ray of wavelength 1 A o after striking the target?  λmin = 124

How does the pressure exerted by a typical brick, A typical brick has dimen...

A typical brick has dimensions of  20.0 cm x 10.0 cm x 5.0 cm and weighs 20.0 N. How does the pressure exerted by a typical brick when it is resting on its smallest side compa

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

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