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

Consider the temperature distribution, Consider the temperature distributio...

Consider the temperature distribution in a 1D flat plate, insulated at x = L and exposed to convective heat transfer at x = 0. On the axes below, sketch what the distribution looks

Huygens wave theory, Huygens wave theory: Huygen's wave theory is not c...

Huygens wave theory: Huygen's wave theory is not correct in all respects. 2. It assumes simply that light energy is propagated as a wave. 3. At the time of his proposition

Measure of elapsed period using the si unit, Q. Measure of elapsed period u...

Q. Measure of elapsed period using the SI unit? Answer:- 1. This is the question that each true scientist dreads to be asked especially in a public setting by extremely in

Pendulum, a pendulum is timed ,first for 20 swings and then for 50 swings ;...

a pendulum is timed ,first for 20 swings and then for 50 swings ; time for 20 swings = 17.4 sec and time for 50 sec = 43.2. calculate the average time per swing/

Projectile motion - distance from the launch point, A projectile is launche...

A projectile is launched from zero height with an initial angle, θ, above the horizontal and with an initial velocity, vi. a. Show that the range of the projectile the distance

Expermient of containers from used electric bulbs, Containers from used ele...

Containers from used electric bulbs Used electric light bulbs can be made into containers that will substitute for flasks, beakers, test tubes and same devices. With reasonable

Define electric flux, Q. Define: Electric flux. Give its unit. The elec...

Q. Define: Electric flux. Give its unit. The electric flux is described as the total number of electric lines of force crossing through the given area and its unit is Nm 2 C-1

Define the cylinders with massive piston, Define the Cylinders with Massive...

Define the Cylinders with Massive Piston? Assay moles of an ideal monatomic gas placed in a vertical cylinder. The top of the cylinder is blocked by a piston of mass M and cro

Newton law, Newton 2nd law of motion proof

Newton 2nd law of motion proof

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