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

Determine the final temperature of the system, A beaker of water sits in th...

A beaker of water sits in the sun until it reaches an equilibrium temperature of 30°C. The beaker is made of 100 g of aluminum and contains 170 g of water. In an attempt to cool th

Angular Momentum, In the experiment, under which of the following circumsta...

In the experiment, under which of the following circumstances is the angular momentum L of the movable puck NOT conserved? a) The net torque  = 0. b) The radius r is always perpen

Describe potential difference between two points, Describe a) Potential ...

Describe a) Potential difference between two points V, B) Intensity of electric field E. Derive the relation between them.

What do you mean by sound absorber, What do you understand by reverberation...

What do you understand by reverberation time an auditorium What do you mean by sound absorber. Give two examples for good absorbers.

What are solar cells, Solar Cells: The solar cells that we see on calculat...

Solar Cells: The solar cells that we see on calculators and satellites are photovoltaic cells or modules (modules are easily a group of cells electrically  connected and packaged

Estimate the value of energy of dissociation, 1. The probability of dissoci...

1. The probability of dissociation of water into H + and OH - , to a good approximation, can be characterized by the Boltzmann distribution:  W ≈ e -Eα/ KT If, at 27°C, 1.

Dual nature of light, Dual Nature of Light: As light is accepted as a f...

Dual Nature of Light: As light is accepted as a form of waves as well as packets of photon. This nature of light is known as dual nature of light.

Explain diffraction grating and the screen, A diffraction grating with slit...

A diffraction grating with slits separated by 3.40 x 10 -6 m is illuminated by light with a wavelength of 589 nm. The separation between lines in the diffraction pattern is 0

Explain the term work function of a metal, Explain the term 'work function'...

Explain the term 'work function' of a metal. The threshold frequency of a metal is f 0 . When the light of frequency 2f 0 is incident on the metal plate, the maximum velocity of e

What is the kinetic energy of the block subsequent, A block of mass m on a ...

A block of mass m on a plane horizontal frictionless surface is pushed up against the end of a horizontal spring the other end of which is connected to a wall therefore that it com

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