# Thread: Push or Pull Electricity.

1. ## Push or Pull Electricity.

While this may sound stupid It's something i don't understand..

In elecrticity is it a push or pull flow? What i mean is..

I've got 5 X 12V Cables Running into a Terminal Strip. I have 1 cable out.

Is the device at the end of that cable going to PULL just what it needs or are those 5 cables going to PUSH more than it can handle.

Yes it may sound dumb but my electronic skills.. Well.. SUCK. :d

2. remember there is no "at the end of the cable" per se, it loops back to the source through ground. Voltage at the source (actually the difference in voltage between the source and ground) tends to push current.
If you connected a million cables from terminal to terminal on the battery, something like infinate amps would flow, the cables, offer little to no resistance to current flow (due to such a large cross sectional area).
So current in a circuit is determined not only by the voltage but by this resistance as well. Thus, ohms law (variation) I = E/R.
So from that you can see that the load, or what your hooking up at the end, determines current flow, no matter how many cables you hook up to it.
Voltage pushes, loads allow current to pass (and determine how much given a particular voltage).
Cables just need to be chosen so that the current the load wants wont be to much for them.

EDIT: But technically, to fully answer the actual question, + pushes, - (ground) pulls, (equally) and loads resist. The device will allow just what it needs if it's working right, no matter how big or how many cables you have going to it. Too much is ok (cables that is, not voltage).

I bet I'll hear about electron-flow now. But I was just trying to not be too confusing, so I stayed with the hole-flow convention.

3. That lot was confusing to me and I am an electrical engineer!!

Think of it as water, the + is the mains water and the drain is the - along with the pipes being the cables.
You can now think of the tap as being a resistor, the more closed the tap the higher the resistance and the less current/water will flow.

4. Sorry. I never was very good in english class.

5. yep, water is the best way to explain it . . .

Current = water flow
Voltage = water pressure

6. Actually, atoms have 7 electrons and when you introduce an atom on one end that has 8 and on the other end one that has 6, they all shift over to equalize. You need both sides for it to happen.

The important thing is to have a big enough wire to supply the load otherwise it becomes a fuse. Anything larger than required will still only supply what's required.

7. Well in reality, electricity is the flow of negative electrons, so current really flows from - to +. But electrical engineers like to use conventional flow where they treat the current as going from + to -. So when you attach those peripherals to the +12 volt lines, in reality the peripherals can be thought of as pulling electrons from the negative ground terminal and pushing them back out of the +12v terminal. On paper however, most engineers usually draw conventional current, where the current is going from the +12v to ground. It doesnt really matter which direction you draw the current as going, as long as you stick to that same convention throughout your calculations and you will get the same answer.

8. I knew it.

9. Originally Posted by h3rk
Originally Posted by nobb
Originally Posted by h3rk
I bet I'll hear about electron-flow now. But I was just trying to not be too confusing
Well in reality, electricity is the flow of negative electrons, so current really flows from - to +
I knew it.
haha

10. Your all wrong as everybody knows electricity is really made of smoke and not electrons!!! If this wasn't the case then letting the smoke out of electronic circuits wouldn't make any difference and it would still work

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