The generation of arc

When using switch electrical disconnect current,if the circuit voltage not less than 10-20 v,current not less than 80~100 ma,electrical contact between will produce electric arc.Arc is free gas of high temperature and high electrical conductivity,it not only has a lot of damage to contact,and prolongs the time that disconnect circuit.Therefore,in the structure and working condition of the switch

electric acmotortrading.blogspot.com before,first to

see how its produce and put out.The formation of the arc is contact between neutral protons

(molecules and atoms) is the process of free.Switch contact separation,the distance between the

contact is small,high electric field intensity E (E = U/d).When the electric field intensity exceeds

3 x 1000000 v/m,the electrons on the surface of the cathode electric field force will be pulled out

of the free electrons to form a contact space.

This free way is called:strong field emission.The free electrons emitted from the brake

rotorcathode surface and the contact between the original a few electronic,in under the

action of electric field force to accelerate the anode movement,constantly and neutral particles collide on the magnetic motor way.As long as the electronic velocity v is

high enough,the kinetic energy of the E = mv2 is enough big,can from the nature of playing

electronic,the formation of free electrons and positive ions.This phenomenon is called collision

free.New form of free electrons also accelerated motion to the anode,similarly will free with neutral particle collisions.Collision ionization is continuously as a result of the contact between full of electrons and positive ions,greatly conductance; Under the applied voltage,arc medium is punctured,the circuit again by conduction.

Contact arc burning gap between called arc gap.Arc,arc gap between the heat on the surface of the cathode of the electrons gain enough energy and emission,outward form thermoelectricity field emission.At the same time under the action of high

temperature (arc center part to electric motors

pricemaintain the temperature can reach more than 10000 ℃),irregular hot gas neutral

particle movement speed increase.When have enough kinetic energy neutral particles collide with each other,will be free and form electrons and positive ions,this phenomenon is called thermal dissociation.Increase with the distance separate contact,the contact between the electric field intensity E gradually decreases,and the arc combustion is mainly rely on thermal free

maintain.Between switch electric contact,free process at the same time,also happening to the

disappearance of a charged particle free process.