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

Vernier calliper , measurement and calculation with formula

measurement and calculation with formula

Uses of ultrasonics, Uses of Ultrasonics: 1. Ultrasonic are used in dia...

Uses of Ultrasonics: 1. Ultrasonic are used in diagnosis of disease, physical therapy as surgical tool & industry. 2. They are used in sounding devices to calculate the dept

Determine the maximum generated emf - magnetic field, A rectangular coil of...

A rectangular coil of sides 8cm by 6cm is rotating in a magnetic field such that the longer sides cut the magnetic field. Calculate the maximum generated e.m.f. if there are 6

Three phase system over single phase system, Advantages and disadvantages o...

Advantages and disadvantages of three phase system over single phase system    1. In a single phase circuit the power distributed is pulsating. In three-phase system the total

Evaluate the speed of the block, Evaluate the speed of the block A 2.00-...

Evaluate the speed of the block A 2.00-kg block is attached to a spring force constant 500N/n. The block is pulled 5.00 cm to the right of the equilibrium and released from rest

Find the lowest frequency for which destructive interference, Find the lowe...

Find the lowest frequency for which destructive interference Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 2.00 m

When are intermolecular forces the strongest, When are intermolecular force...

When are intermolecular forces the strongest? Intermolecular forces (dipole-dipole, dispersion and hydrogen bonds). These forces are weaker than chemical (covalent) bonds. Thus

Explain electric potential difference, The electric field strength, defined...

The electric field strength, defined as a force per unit charge, has the units Newton per coulomb, N/C. The formula for electric potential difference, ΔV = Ed, though, suggest

Volume observed by an observer stationed on the earth, A cube of side ‘a' i...

A cube of side ‘a' is moving with speed 0.6 c normal to one of its face. What is its volume observed by an observer stationed on the earth ? The volume of cube = a x a x a = a 3

What is electric flux, What is electric flux? Write its S.I. units. Usin...

What is electric flux? Write its S.I. units. Using Gauss's theorem, assume an expression for the electric field at a point because of a uniformly charged infinite plane sheet.

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