MJLorton Solar Power and Electronic Measurement Equipment Forum
General Category => General Discussion => Topic started by: dvisor on December 23, 2017, 08:05:32 PM
-
Hello everybody
I have a question that's been bugging me for some years now, I'll try to explain the best I can
* I do understand that the flow of electrons generate at the negative pole from the battery
* Yet it is universally stated that the positive lead is the one known to "have" the electricity, I do know already that this is a historical mistake and not a big deal and that's why it has not been correct through all this time (which in fact bugs me a lot being sometimes obsessive-compulsive myself)
Now, here's were I'm confused and a lot of questions arise:
- On an AC circuit at a house, if I use a neon screwdriver (I know those are dangerous, please bear with me for this question's sake) and separate/identify the "Hot" wire from the "Neutral" wire, should I call the "hot" wire as positive?
- Why if the Hot wire is in fact the positive and it is not carrying any electrons does it provides the power to turn on the neon bulb?
- Why the neon screw driver doesn't lights up on the "Neutral" wire?
I know there's something I'm missing here but I just can't figure it out
-
* I do understand that the flow of electrons generate at the negative pole from the battery
Nope. There are no "generated" electrons. The electrons are already in the wire. The voltage source only moves them in a specific direction.
(Water analogy: The voltage source is a pump. The hose is already filled with water.)
(http://i.imgur.com/c5oHuEH.gif)
* Yet it is universally stated that the positive lead is the one known to "have" the electricity, I do know already that this is a historical mistake and not a big deal and that's why it has not been correct through all this time (which in fact bugs me a lot being sometimes obsessive-compulsive myself)
Physically: The electrons are flowing from negative to the positive.
In electronics: They just flow from positive to negative. Much more simple...
[/quote]
- On an AC circuit at a house, if I use a neon screwdriver (I know those are dangerous, please bear with me for this question's sake) and separate/identify the "Hot" wire from the "Neutral" wire, should I call the "hot" wire as positive?[/quote]
No, never. The hot wire changes the polarity fifty or sixty times per second from positive to negative. (Water analogy: The voltage source is a pump, pressing water in a hose, then sucking it back, pressing it again, sucking it back... and so on and on.)
- Why if the Hot wire is in fact the positive and it is not carrying any electrons does it provides the power to turn on the neon bulb?
As you have read above: There are already electrons in the wire and a voltage present. The only reason for nothing happend yet is: Current can only flow if there is a closed circle. With the neon screwdriver you are closing the circle. The path is now: Voltage source - wire - screwdriver - your body - earth - voltage source.
Additional: The human body has some capacity.[/quote]
- Why the neon screw driver doesn't lights up on the "Neutral" wire?
AC is generated with alternators/generators, working with 3 phases. The phases are shifted at 120°. All three phases added are zero Volt. At the outlet of the voltage sorce are three separated phases. One of them is your hot wire. On the other side of the voltage source are the three phases tied together. Again: This results in 0 V. This is your neutral. And is typically connected with earth. (Not in your single wall outlet, but often at a central point in your house wiring and for sure at the generator.)
(https://lh5.googleusercontent.com/-nz0iPJ7T4Wo/VFfx1LZdGhI/AAAAAAAANCs/mPg2PUhJ00Y/w517-h381/threephase.gif)
-
ProBang2
Right now I'm on that funny spot were you finally get a grasp on something that has confused you for so long, an eureka moment to say the least.
I have no words to express my gratitude, the pieces you provided were very important to fully grasp the basics, I even went further and derived the understanding of threephasic current from your explanation, that's how useful it was, thank you very much
-
Glad, i could help. :)
-
How Can Help?