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

Define force, Force: push or pull upon an object resulting from the object...

Force: push or pull upon an object resulting from the object's dealings with another object. Whenever there is an interaction among two objects, there is a force upon every of

Law, What is meant by gravitational law?

What is meant by gravitational law?

Obtain relativistic expression for the kinetic energy, Obtain Relativistic ...

Obtain Relativistic expression for the kinetic energy of the particle.

State the demerits of ultrasonic magnetostriction method, Illustrate the de...

Illustrate the demerits of ultrasonic magnetostriction method. Limitations of ultrasonic magnetostriction method: a. This can produce frequencies up to 3 MHz simply. b.

Explain efficiency, An electric motor with a load delivers 5.2 hp to its sh...

An electric motor with a load delivers 5.2 hp to its shaft (1 hp = 746 W). Under these conditions, it operates at 82.8 percent efficiency. a. How much current does the motor d

Transition metal catalyst , Hydrogenation reactions are facilitated by the ...

Hydrogenation reactions are facilitated by the use of a transition metal catalyst such as Ni or Pt. Predict the signs of ΔH, ΔS and ΔG when hydrogen gas is adsorbed onto the surfac

State the forward characteristic of zener diode, Forward Characteristic of ...

Forward Characteristic of Zener diode Connect the circuit demonstrated in fig (a) using the 5.1 V zener diode. For forward characteristic, reverse the connection of zener di

What is diffusion current , Because of concentration difference holes or el...

Because of concentration difference holes or electron try to vary from their side to other side. Only these holes or electrons cross the junction, having high kinetic energy. This

Typical signal source and amplifier circuit, 1. Discuss the internal noise ...

1. Discuss the internal noise sources that are present in a typical signal source and amplifier circuit, and describe their effects.  2.  The company currently has a low noise a

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