Flow of Electrons

[chaco]

OK this is really BUGGING me. Which way does electricity really flow ?
From the Positive out to the Load and back to Ground....or the other way.
I have heard both versions and would like to get it right when I explain it to
my kids on how to trouble shoot 12V electrical systems on a Boat :nerd:
And why do we ALWAYS Switch the Positive lead

Happy Batteries

 

[Bob Grenier]

Which Way ?

Check this out.
http://www.eskimo.com/~billb/amateur/elecdir.html

 

[chaco]

Eyeeeeee Corumba !

Great Article !......... Now my Head Hurts
Guess I just tell the Kids that electricity is Tricky and flows in both directions

Nice Try figuring out this One

 

[footrope]

Direction of electron flow is sort of irrelevant

For troubleshooting problems, the direction of flow is not going to help find a broken wire. Or, if you're blowing fuses, that won't help you find the shorted section of the wiring. It just doesn't enter into the solution. So you can introduce flow or not when teaching electricity and how to solve problems. The important thing is that there is a path, provided by the wires, for the electricity to flow.

The switching of the positive lead is a convention - a choice made by designers of electrical circuits - and probably has a very interesting history. You can switch either lead and the results would be the same. All you are doing is providing a path for the flow, or interrupting it. In a car, which has a common path called the chassis, connected to the negative battery post, it is usual to switch the positive lead.

The use of a common ground, like a bus bar or the frame of a car, makes it possible on a car to run one wire to light that dome light in the ceiling, instead of two. The other contact for the light bulb can be connected with a short wire to the nearby metal roof of the car. On a plastic boat, we don't have this luxury and we always have to run two wires from our electrical panel to the device.

Have fun teaching the kids.

 

[chaco]

Why ?

Thanks Guys
I can work on these things and troubleshoot pretty well....just needed to get
ready for the WHY Part

 

[rwthomas1]

I just try to not let the "magic smoke" out of the wires.... RT

 

[gareth harris]

In the everyday world of electronics, these particles are the electrons and protons supplied by atoms in conductors.

Sorry, but that article is only worth its comedy value. Electronic components do not break down and vent hydrogen in order to carry electric charge. In modern solid state electronics, the charge is often carried by a 'positive hole' - I can not explain that without going through undergraduate level quantum mechanics.

To answer the basic question, electrical current is a flow of electrical charge, which can be carried in numerous different ways of both positive an negative charge carriers. But on a boat DC system, it can be simplified to think of the circuit originating at the battery, and that the charge has to follow it all the way around. For the most part, the flow is carried in a negative to positive direction by electrons; but not everywhere, such as within the battery itself.

For AC systems, I recommend Nigel Calder's book, which explains them extremely well.

Gareth
Freyja E35 #241 1972