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Same polarity but different direction of current flow. How annoying!
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tkamiya:
But, but, but....  SIR!  I'm older than you and I got used to it.   :scared:
helius:

--- Quote from: tkamiya on September 23, 2020, 05:54:05 am ---When we did understood electrons, we found out that electrons actually flow from negative to positive.  So what you are observing is correct.  To rectify this situation somewhat, explanation that "hole" (location of absence of electron) moves the same way current moves.
--- End quote ---
The hole is a real phenomena that only exists in p-type semiconductors. The wires in basic electric circuits definitely do not conduct by means of holes!


--- Quote from: tkamiya on September 23, 2020, 05:54:05 am ---BUT, there is nothing flowing from positive to negative.
--- End quote ---
Batteries and wires are human inventions, not fundamental physical objects. It is undesirable to define the latter for the convenience of the former.

In general, the conception that "electrons are moving like little corpuscles in a tube" is just naïve and misleading. Electrons do not even have a definite location and thus the idea that they are "flowing from negative to positive" is wrong. This wrong intuition gives rise to a host of other wrong ideas, like the idea that electrons "start out" from the negative terminal and must travel around the circuit before entering the positive terminal, so they must flow very quickly because current is equal in both branches from the moment the circuit is completed. Visualizing electrons flowing is the sign somebody doesn't understand electronics.
Berni:
So what about charging a battery? In that case you are also pushing current into the battery positive terminal.

The reason the positive terminal is called the positive terminal because it is at a higher electrical potential than the negative terminal. But the flow of electrons is dictated by a difference of potentials, so as soon as you connect two different voltage potentials that starts pulling electrons along and you get current.

So when you are changing a battery then the charger is creating an even higher voltage potential than the positive battery terminal. So since current flows from a higher potential to a lower ones means that the current starts flowing towards the battery + terminal.

Then when you connect a load to the battery you connect it between the positive and negative terminal. So in that case the batteries positive terminal is higher potential than its negative terminal so current flows out of the positive terminal, to the load and back down to the low voltage negative terminal.

You can imagine wires being water pipes, voltage is water pressure, current is water flow. It always flows from high pressure to low pressure.
BravoV:

--- Quote from: Berni on September 24, 2020, 08:09:04 am ---You can imagine wires being water pipes, voltage is water pressure, current is water flow. It always flows from high pressure to low pressure.

--- End quote ---

I always used this example when I explained this to friends or youngsters asking this, similar but slightly different example, as at some audiences, like to ask what if the pipe break or burst ? And where the water goes ?  ::)

I used wire = blood vein , current = blood "flow" (not the blood it self, but the flow, and the blood must ALWAYS be there in the vein) and voltage = blood pressure, also to spice things up, heart is the battery/power source.

This example, hopefully will suppress the pipe burst question, and my case it worked all the times.  ;D

Of course, should they ask about the pipe/vein burst or blood spillage, all I need to answer is .. ITS BAD !  :-DD
ChristofferB:
Keeping in the analogy, the answer could be to compare a burst pipe to a short to ground. A high flow (low impedance) path to the lowest elevation/potential
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