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 flux density, A closed magnetic circuit of cast steel have a ...

A closed magnetic circuit of cast steel have a 6cm long path of cross-sectional area 1 cm 2 and a 2 cm path of cross-sectional area 0.5cm 2 . A coil of 200 turns is wound arou

Define Displacement: , Displacement: - The modification in position of a bo...

Displacement: - The modification in position of a body in a certain direction is known as displacement. It is a vector function and its unit in SI system is meter.

Introduction to physics, what is meant by physics? and also explain the br...

what is meant by physics? and also explain the branches of physics.

What are the semiconductor devices, What are the Semiconductor Devices? ...

What are the Semiconductor Devices? A semiconductor is a material whose conductivity is much less than a conductor (such as copper), but greater than that of an insulator (such

Communication physics, In a transmitter the final stage class C amplified ...

In a transmitter the final stage class C amplified with 18V DC supply calculate what equivalent Road the transistor to an antenna with 50ohm load impedance design and draw an L n

Nuclear decays, Nuclear Decays Uses a proper Monte Carlo engine to simu...

Nuclear Decays Uses a proper Monte Carlo engine to simulate real decays.The decay of 500 atoms of the fictional element Balonium.

Detremine the phase and line currents, Three coils each having resistance ...

Three coils each having resistance 3 Ω and inductive reactance 4Ω are linked (i) instar and (ii) in delta to a 415V, 3-phase supply. Calculate for each connection (a)

Name the device used for data transmission, Name the device used for data t...

Name the device used for data transmission from single computer to an other Justify the name. Using this device draw the block diagram for data Communication and define it brief

State and explain flemings left hand rule, What is the net force on a condu...

What is the net force on a conductor of length l carrying current 'i' when it is situated in a magnetic field of induction B? When is it maximum? State and explain Fleming's l

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