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

Time base control 2, Time Base Control 2 Shows the effect of modifying ...

Time Base Control 2 Shows the effect of modifying the time base control on the show while there is an input voltage varying in time.

Inelastic collision, Inelastic Collision Collisions among objects are g...

Inelastic Collision Collisions among objects are governed through laws of momentum and energy. While a collision occurs within an isolated system, the total momentum of the sys

Why capacitor blocks d.c. but allows a.c., Q. A capacitor blocks d.c. but a...

Q. A capacitor blocks d.c. but allows a.c. Why? Capacitive reactance   XC = 1/ω C        = 1 / 2πν C Where ν is the frequency of the a.c. supply. In a d.c. circuit

Highest electrical resistivity, Highest electrical resistivity exists in wh...

Highest electrical resistivity exists in which wire??? nichrome wire.

Ripple tank, Ripple tank The concept of reflection and refractio...

Ripple tank The concept of reflection and refraction of light waves can be understood by the study of reflection and refraction of waves on water. The water waves travel

Reflection and refraction of waves, When rays are incident on a boundary am...

When rays are incident on a boundary among medium, a section of incident waves goes back into the initial medium whereas the remaining is sectionaly absorbed and sectionaly transmi

.work power and energy, work done by conservative force on a system is equa...

work done by conservative force on a system is equal to

What is the rotational acceleration of the merry-go-round, The rotational v...

The rotational velocity of a merry go round is increased at a constant rate from 1.5 rad/s to 3.5 rad/s in a time of 9.5 s. What is the rotational acceleration of the merry-go-

Describe critical angle, With a neat and clean diagram illustrate in brief ...

With a neat and clean diagram illustrate in brief the TIR. Describe critical angle and mention the two conditions for TIR.

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