Hi i know that voltage say supplied from a battery is created by certain chemical; processes which occur in it, but where does current come from? Does current allready exist in the potential electrons in the materials atoms and current is when the voltage causes the electrons to "break loose" and the voltage then forces these electrons around the circuit hence current? I dont know can anyone help me.

 

Originally posted by Nirvana@Jul 16 2005, 11:16 PM
Hi i know that voltage say supplied from a battery is created by certain chemical; processes which occur in it, but where does current come from? Does current allready exist in the potential electrons in the materials atoms and current is when the voltage causes the electrons to "break loose" and the voltage then forces these electrons around the circuit hence current? I dont know can anyone help me.

[post=9110]Quoted post[/post]​

Have a look at this tutorial

http://www.allaboutcircuits.com/vol_1/chpt_1/2.html

 

Originally posted by Nirvana@Jul 16 2005, 03:16 PM
Does current allready exist in the potential electrons in the materials atoms and current is when the voltage causes the electrons to "break loose" and the voltage then forces these electrons around the circuit hence current?

[post=9110]Quoted post[/post]​

Actually, there's not a lot of "breaking loose" going on. One of the many nifty things about metals and other conductors is that the electrons are already loose. This is the "realative mobility of electrons" refferred to in the tutorial that Pepe linked to. Some metallurgists refer to this as "a sea of electrons moving freely and randomly through the crystal lattice."

Note that in many applications, only a fraction of the electons are actually being pushed around by the applied voltage. One ampere of current is associated with a mere 6.24 x 10^18 electrons. There are more than five times that number of atoms in a single cubic millimeter of copper!