Confused about voltage at electron level

AI Thread Summary
Understanding voltage at the electron level involves recognizing that voltage is meaningful only as a difference between two points, and it relates to the electric field. In the context of an NMOS transistor, minimal current is drawn at the gate due to its high impedance, and voltage changes can propagate along a trace as a wave. The movement of the electric field is not about accumulating more electrons but rather the same electrons moving faster in response to the voltage applied. The visual representation of voltage differences, such as between 3V and 5V lines, does not imply more electrons but rather indicates a stronger electric field. Ultimately, the behavior of electrons and field lines is governed by their interactions and the properties of the materials involved.
NoName707
Messages
6
Reaction score
0
Ok, so I've been struggling with understanding voltage down to the electron level. I know a voltage by itself has no meaning. We want a voltage difference. i.e. voltage diff between point A and B and that ground really has no meaning except as a reference. and i know that current is the movement of charge and that voltage is the electric field. my question is as follows.

Say I have an NMOS transistor which i am turning on and off with a switch. being a high impedance input (gate) there will be very minimal current draw.perhaps current to charge the line+gate capacitance and leakage current. If this is considered a transmission line, we will see the voltage move down the trace as a wave perhaps taking 1ns to move 6 inches. what exactly is happening here? How is the electric field moving down? is the voltage proportional to the number of electrons? i know the voltage is a force, but the force has to come from something.

Thanks!
 
Engineering news on Phys.org
let me first state that i don't know what I'm talking about :biggrin: but i'll try. from what i know it is the fact that the gate had been doped so that it's missing electrons, and all that's happening a middle layer of doped silicon that has been depleted of an electron in the outer layer of atoms in a boron-silicon bond gets back it's electrons allowing an two/three layers of doped phosphorus-silicon bond with extra electrons to pass (jump to the next outer shell of the next closest conductor). the reason for the high capacitance and resistance is because of the area of the gate, the small breakdown voltage of the gate is due to how thin it is. the current from drain to source should be proportional to the voltage at the gate.
 
light_bulb, thanks! i was actually talking more about the electric field moving down the trace as a wave. If i were to visually depict the voltage on a trace what would a 3V line look in comparision to a 5V line? just more electrons? I didn't think electrons could just bunch up next to each other because their fields would tend to push them away from each other.

I know there are will be more "field lines" but what causes these extra "field lines"
 
NoName707 said:
If i were to visually depict the voltage on a trace what would a 3V line look in comparision to a 5V line? just more electrons? I didn't think electrons could just bunch up next to each other because their fields would tend to push them away from each other.

I know there are will be more "field lines" but what causes these extra "field lines"

not more electrons, the same electrons moving faster as far as the other questions i haven't jumped into the physics type stuff like electromagnetics yet.
 
Hi all I have some confusion about piezoelectrical sensors combination. If i have three acoustic piezoelectrical sensors (with same receive sensitivity in dB ref V/1uPa) placed at specific distance, these sensors receive acoustic signal from a sound source placed at far field distance (Plane Wave) and from broadside. I receive output of these sensors through individual preamplifiers, add them through hardware like summer circuit adder or in software after digitization and in this way got an...
While I was rolling out a shielded cable, a though came to my mind - what happens to the current flow in the cable if there came a short between the wire and the shield in both ends of the cable? For simplicity, lets assume a 1-wire copper wire wrapped in an aluminum shield. The wire and the shield has the same cross section area. There are insulating material between them, and in both ends there is a short between them. My first thought, the total resistance of the cable would be reduced...
I am not an electrical engineering student, but a lowly apprentice electrician. I learn both on the job and also take classes for my apprenticeship. I recently wired my first transformer and I understand that the neutral and ground are bonded together in the transformer or in the service. What I don't understand is, if the neutral is a current carrying conductor, which is then bonded to the ground conductor, why does current only flow back to its source and not on the ground path...
Back
Top