Understanding the Importance of Proper Grounding in Single Wire Transmission

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Discussion Overview

The discussion revolves around the necessity of grounding in single wire transmission circuits, particularly focusing on the role of grounding in completing circuits and facilitating current flow. Participants explore concepts related to circuit completion, voltage maintenance, and the behavior of specific devices like Van de Graaff generators.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question why the source must be grounded, noting that while grounding completes the circuit, they seek to understand the underlying reasons for current flow without it.
  • One participant suggests that without a complete circuit, it is impossible to hold voltage constant at the source and draw current as needed, using the Van de Graaff generator as an example.
  • Another participant emphasizes that a complete circuit is necessary for current to flow, comparing the situation to needing to connect both terminals of a battery.
  • Some participants express confusion regarding the Van de Graaff generator's operation, suggesting that as long as there is a buildup of electrons in the ground, it should function without a complete circuit.
  • There is a reference to a figure from a Wikipedia page illustrating that current flows in a closed path, regardless of how the ground is defined in the circuit.

Areas of Agreement / Disagreement

Participants generally agree that a complete circuit is necessary for current flow, but there is disagreement regarding the specific implications and functionality of grounding, particularly in the context of the Van de Graaff generator example. The discussion remains unresolved regarding the feasibility of drawing current without a complete circuit.

Contextual Notes

Participants express uncertainty about the operation of the Van de Graaff generator and its relationship to grounding, indicating a need for further clarification on the assumptions involved in these scenarios.

MotoPayton
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https://mail.google.com/mail/?ui=2&...&th=13350dc1754a8105&attid=0.0&disp=inline&zw

Can someone explain why the source must also be hooked up to ground. I know it completes the circuit but what's the point? Why wouldn't current flow without it? Since the line is at a positive potential then there is a resistor(acting as a house) then house is connected to ground. Seems as if current should flow from high to low potential.

Having a dumb day can't figure stuff out.
 
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MotoPayton said:
https://mail.google.com/mail/?ui=2&...&th=13350dc1754a8105&attid=0.0&disp=inline&zw

Can someone explain why the source must also be hooked up to ground. I know it completes the circuit but what's the point? Why wouldn't current flow without it? Since the line is at a positive potential then there is a resistor(acting as a house) then house is connected to ground. Seems as if current should flow from high to low potential.

Having a dumb day can't figure stuff out.

Your link requires a secure sign-in and password. Can you post is in the clear somewhere else?
 
1029111104.jpg
 
Yes, in this circuit the source has to be grounded. Otherwise the circuit is not complete, and no current can flow through the signal source.

Alternately, just draw a wire across the bottom of the signal source and the load resistors, and get rid of the ground symbols. They just represent a common connection in this problem anyway.

Think of the signal source like it was a battery. You need to connect to both the + and - terminals of a battery to get any current out of it, right?
 
So without a complete circuit is there a way to hold the voltage constant at the source and draw current when necessary?

If you had a van de Graff(not touching the ground) and a wire hooked up to the top connected to resistor that connected to the ground, shouldn't it have a steady current.
 
MotoPayton said:
So without a complete circuit is there a way to hold the voltage constant at the source and draw current when necessary?

If you had a van de Graff(not touching the ground) and a wire hooked up to the top connected to resistor that connected to the ground, shouldn't it have a steady current.

I don't know much about Van de Graff generators, but no, without a complete circuit, no current will flow. Keep thinking about my battery illustration. If you connect only one end of a battery to anything, nothing happens, right?
 
I believe you on the battery and everything and that makes sense but I don't understand why my Van de Graff example will not work..
As long as there is build up of electrons in the ground then there will be no counter electric field and it should work.
 
Last edited:
MotoPayton said:
I believe you on the battery and everything and that makes sense but I don't understand why my Van de Graff example will not work..
As long as there is build up of electrons in the ground then there will be no counter electric field and it should work.

Look at the figure at the wikipedia page for the VdG generator:

http://en.wikipedia.org/wiki/Van_de_Graff_generator

It shows a complete circuit, right? The electrons get pumped to "ground" or the - return lead. The arc that gets drawn across the gap flows as the same current all throughout the circuit.
 
If you had a van de Graff(not touching the ground) and a wire hooked up to the top connected to resistor that connected to the ground, shouldn't it have a steady current.

That's my question. I just used the van de Graff in my question becuase it provides a constant voltage and charge on surface.
 
  • #10
MotoPayton said:
If you had a van de Graff(not touching the ground) and a wire hooked up to the top connected to resistor that connected to the ground, shouldn't it have a steady current.

That's my question. I just used the van de Graff in my question becuase it provides a constant voltage and charge on surface.

Looking at the figure at the wikipedia article, it does not matter a bit if you hook "ground" or "Earth" or a pink poodle to the - connection. The current flows around the closed path shown in the figure.

(Not that I have anything against poodles)
 

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