Timeline for How can a buried terminal have different potential than earth potential?
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| Jun 11, 2020 at 15:10 | history | edited | CommunityBot |
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| Sep 15, 2015 at 12:55 | vote | accept | CommunityBot | ||
| Sep 15, 2015 at 9:05 | answer | added | Simon B | timeline score: 1 | |
| Sep 15, 2015 at 4:58 | comment | added | user57037 | I apologize, but I do not have time to read the patent, nor the inclination to defend it. I will say that when metal is placed in moist earth, there can be electric potential caused by the chemical/electric properties of the metals. And if you place a zinc spike next to a copper spike in moist earth, you will certainly be able to measure a potential difference between the two spikes. Basically, you have made a battery, and the earth itself is the electrolyte. | |
| Sep 15, 2015 at 4:39 | comment | added | user86330 | @mkeith Thanks. Let's assume, for the sake of discussion, that currents somehow flow in ground. In this case, do you know the explanation for Dolbear's patent description; which says on a ground plate buried in ground you can get a potential which is higher than the ground potential. Should not it be that plate potential equals the ground potential, since they are in contact (if two wires are connecting without isolation and if there is no resistance between them they have the same potential- from circuit theory). How can Dolbear be right on his description his apparatus? | |
| Sep 14, 2015 at 21:38 | comment | added | user57037 | In a small recently built building, the electrical system will usually be connected to earth in one single place with a spike. From that spike, wires will be used to convey GROUND potential all over the building where electricity is needed. Normally, these wires are not used to conduct current. Any current which flows through the ground wire is considered a fault current. So this wired ground should normally have the same potential everywhere unless a fault occurs. | |
| Sep 14, 2015 at 21:28 | comment | added | user57037 | This topic can become kind of lengthy. Normally, when you are looking at a schematic, it is assumed that "ground" has the same potential everywhere and is considered to be 0V by convention. This may not be connected to earth ground. But consider the case of a PCB. Why does current flow on the ground plane? The only way it can flow is if there is a non-zero electric field. But we still call it a ground plane. Most of the time, the electric field in the plane is very small, and potential differences are not important. If they are important, we have to include them in our model. | |
| Sep 14, 2015 at 19:22 | comment | added | user86330 | @mkeith I heard that ground has the same potential everwhere, which is 0 V. How can you create a potential field gradient in this, since 0 V minus 0 V equals 0 V, thus gradient is zero; therefore no force acts upon the supposed charges in the ground. | |
| Sep 14, 2015 at 19:10 | comment | added | user57037 | The circuit creates an electric field in the Earth. If there are mobile charge carriers present in an electric field, the charge carriers will move along the field gradient. | |
| Sep 14, 2015 at 19:06 | comment | added | user86330 | @mkeith Yes! As you said, "through ground back to the other terminal of the energizer". Do you know how this nonconscious electrons find their way back to the energizer? I mean, they could go to any direction. These electric charges complete the circuit and they do it without the return wire, how do they guide themselves back to the energizer? | |
| Sep 14, 2015 at 19:02 | comment | added | user57037 | In my case, electric wires are strung horizontally on insulated posts. The fence energizer has a "hot" terminal and a "ground" terminal. The hot terminal is connected to the fence wires. The ground terminal is connected to a 6 foot (roughly 2m) metal spike in the earth. Around 50 times per minute, the energizer applies a large voltage between the terminals. If an animal is touching the fence during the pulse, current flows from energizer, through fence, through animal back to ground and through ground back to the other terminal of the energizer. | |
| Sep 14, 2015 at 18:57 | comment | added | user86330 | @mkeith Thanks for your attention. I did not know that current flows in dirt/soil/ground readily. But, really, what do you mean by "flows in dirt". Does it mean it goes to all direction on the ground(since no wire to lead its way), or does it find its way back to the power source in your circuit? | |
| Sep 14, 2015 at 18:30 | comment | added | user57037 | Current flows in dirt readily. Could that be the source of all your misunderstanding? You did not realize that dirt is capable of conducting electricity? The range of conductivity varies, but generally, if there is green vegetation around, the soil will be somewhat conductive. When it gets very dry, sometimes the conductivity is very low. I use electric fences with one grounded terminal to keep goats inside a paddock. When it gets very dry, the shock given by the fence becomes measurably and noticeably weaker. | |
| Sep 13, 2015 at 6:26 | comment | added | user86330 | Stack exchange says that this question is put on hold, even though I gave a summary of what I ask. Is not it clear what I am asking? | |
| Sep 13, 2015 at 5:36 | comment | added | user86330 | @mkeith How can the electric current flow in the dirt? Since the terminal ends in the ground, there is an open circuit. Therefore no current should flow. | |
| Sep 13, 2015 at 4:41 | comment | added | user57037 | If you measure the voltage on a terminal buried in ground at different places on the terminal, you will find the potential difference to be very close to zero, unless there is a fairly sizable current flowing through the terminal. But if you measure the Voltage between two different terminals buried in different locations, you may find a substantial voltage difference due to current flowing in the dirt beneath your feet. | |
| Sep 12, 2015 at 20:46 | history | edited | user86330 | CC BY-SA 3.0 |
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| Sep 12, 2015 at 20:35 | answer | added | Phil byrom | timeline score: 0 | |
| Sep 12, 2015 at 19:35 | answer | added | Marko Buršič | timeline score: 0 | |
| Sep 12, 2015 at 19:31 | review | First posts | |||
| Sep 13, 2015 at 1:41 | |||||
| Sep 12, 2015 at 19:28 | history | asked | user86330 | CC BY-SA 3.0 |