Common Electrical misconceptions?

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The discussion centers around common misconceptions in electrical engineering, particularly regarding the flow of electricity and the behavior of electrons. It highlights Benjamin Franklin's incorrect assumption that positive charges flow, which persisted in engineering despite later discoveries by J.J. Thompson revealing that negative charges (electrons) are the ones that move. Participants explore the idea of transmitting electrical energy across a vacuum, noting that while electrons need a medium to flow, electromagnetic waves can travel through a vacuum. The conversation also touches on the role of vacuum tubes and thermionic emission in allowing electron flow without a traditional medium. Overall, the thread emphasizes the complexities of electrical concepts and the need for clarity in understanding them.
  • #31
TheAntiRelative,

You're mixing up a couple of different speeds. The real speed of electrons in a wire is on the order of a hundred thousand meters per second, due to thermal energy. This motion is random however -- approximately the same number of electrons are going left at any given instant as are going right. There is no net movement of charge, but the electrons are zipping around quite rapidly inside the wire.

When you apply an electric field to the wire (by connecting it to a battery, say), the electrons still zip around with approximately the same speed, but now they also slowly drift toward the positive terminal of the battery. Their motion is still mostly random, but they go a little further in one direction than the other, so there is a net movement of charge. The speed of this slight drift toward the positive terminal is called the "drift velocity," and it is, indeed, only on the order of a few centimeters per second in normal electrical systems.

- Warren
 
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  • #32
TheAntiRelative said:
I thought it was just that wave that was traveling that fast and not the actual electrons. In the original article I linked it was stated that the actual electron flow is like centimeters per hour while the wave is the energy that is traveling really fast.

The examples I listed are for electrons accelerated in a vacuum, no wires. Particle accelerators, SEM's and TEM's routinly accelerate electrons to near the speed of light. Electrons flowing through a wire will never see these speeds as chroot explained.
 
  • #33
The aticle is enlightening but a bit misleading as well. Here are my disagreements
with just the first two points.

1) The flow of current IS opposite to the direction of motion of actual
electrons. This is what has confused people. Protons do not move in metallic
conduction.

2) The "electricity" that flows in a wire DOES come from a battery or generator-
if by electricity you mean energy, and that's what most layman mean. Furthermore,
in a DC circuit, the electrons actually DO come from the battery, traverse the circuit and return to it.
 
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  • #34
HI I have an experiment that may not be overunity but possibly close. So I was wondering if you would check what I wrote about it and let me know should it still be running after 8 days or not? http://www.geocities.com/inhabitor2005/
 
  • #35
kawikdx225 said:
The examples I listed are for electrons accelerated in a vacuum, no wires. Particle accelerators, SEM's and TEM's routinly accelerate electrons to near the speed of light. Electrons flowing through a wire will never see these speeds as chroot explained.

Thanks for the info guys! Now I'm going to have to see exactly how a particle accellerator works ;)
 
  • #36
srdickens said:
HI I have an experiment that may not be overunity but possibly close. So I was wondering if you would check what I wrote about it and let me know should it still be running after 8 days or not? http://www.geocities.com/inhabitor2005/

This is not an overunity device. It's a highly efficient electric motor
with almost no load (except small mechanical losses on the bearings
and windage on the crystal.)

I expect it to run for several days. But it's still exciting. This type
of motor can even be run from a single solar cell. Fun fun fun.
 
  • #37
srdickens said:
HI I have an experiment that may not be overunity but possibly close. So I was wondering if you would check what I wrote about it and let me know should it still be running after 8 days or not? http://www.geocities.com/inhabitor2005/

Your crystal is not helping anything. On the contrary, it is unbalancing your motor and wearing the bearings. This is a possible cause for the noise you are hearing.
If you are using an alkaline battery, it's voltage does not change much during discharge. Only after most of the charge is gone, will the voltage drop very quickly.
I agree with Antiphon. You are running a very efficient motor with almost no charge.
 
  • #38
Nixie tubes were generally used for counters.

One nice thing about tube circuits you always knew when there was a problem, especially on motor drives, maximum smoke and flame. The circuits were built on huge slate boards, to keep the curcuits stable. And if there was a bad circuit the whole circiut could be removed and a new one installed 'quickly' and nearby components were unaffected unless it got really hot.

Today with all the solid state if one area melts generally the whole cabinet is toast.