True Ground?

Texasmark

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Dec 20, 2005
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Re: True Ground?

Uh...whatever that is supposed to mean!

A PC power supply, for example, puts out +12, +5, +3.3 and -12V(used for serial ports). Please explain your theory about the minus side of the supply being ground when referring to the -12V source. In actuallity the postive side of the -12V supply is connected to the total power supply ground.

For some reason I thought you had a background in electronics. I guess I was mistaken.

Curious, have you heard of positive ground automobiles? Many British cars were produced that way.

Yes I remember them years ago. Think Ford did it, but don't remember......somewhere around the '50's. They also swapped the location of the + and - terminals on their batteries (some where along the way) so that the - was adjacent to fender (edge of the hood) where the mesh ground wire was attached. So for a lotta years you had to pay attention to where your terminals are and where the terminals are on any replacement battery you purchased.

The Germanium transistor used a negative collector supply whereas the later Silicon used positive which made things easier for the average Joe to deal with the electronic circuits....course that's not the reason for the selected polarities.

Don't know what you are talking about. My reference was to a current motor vehicle's battery, which is usually a single battery of 12v with the - terminal of the battery attached to the engine and frame and becomes the "ground reference". Doesn't matter which terminal is referred to as ground reference, just polarities of everything are opposite....no biggie.
 

Silvertip

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Re: True Ground?

One more thing to add to this fire! Some trailers have the tongue bolted to the rest of the trailer frame. Tilt trailers are an example of this. Unless a short jumper is added around any bolted joints in the electrical path from the tongue to the back of the trailer a ground cannot be reliably achieved for the lights. This is why some folks like to run the white ground wire all the way to the light on one side of the trailer and then across to the other side, or split the circuit at the tongue and run a separate wire down each side to the light. I've never had to resort to that but it is a solution for those experiencing "ground" problems.
 

smokeonthewater

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Dec 3, 2009
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Re: True Ground?

Last month I repaired the wiring on a tracker trailer that had separate grounds from the factory. P/O had screwed it up but the original wiring was fine once put back together. Nothing wrong with running wires for ground, just not usually needed. In a case where the trailer frame doesn't work the best for it as silvertip mentioned it can be a good solution.

BTW I'm pretty sure the O/P has a 12v negative ground system without any germaniums or carnations or flux capacitors or trans-warp coils.
 

Texasmark

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Re: True Ground?

Last month I repaired the wiring on a tracker trailer that had separate grounds from the factory. P/O had screwed it up but the original wiring was fine once put back together. Nothing wrong with running wires for ground, just not usually needed. In a case where the trailer frame doesn't work the best for it as silvertip mentioned it can be a good solution.

BTW I'm pretty sure the O/P has a 12v negative ground system without any germaniums or carnations or flux capacitors or trans-warp coils.

Common Kevin, get a grip man. Bruce and I have had this running gun battle for several years and it's not about to change unless one or both of us get kicked off the forum for nebulous, irrelevant, excaberations of no value that offend the family atmosphere??????? What did I say? Grin
Mark
 

Moody Blue

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May 24, 2004
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3,136
Re: True Ground?

I believe to be entirely accurate, there is no actual GROUND on a vehicle electrical system. There is a COMMON reference point which is the frame of the vehicle which is connected to the (-) battery terminal.
 

BlueLightSpecial

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Dec 2, 2011
Messages
152
Re: True Ground?

I believe to be entirely accurate, there is no actual GROUND on a vehicle electrical system. There is a COMMON reference point which is the frame of the vehicle which is connected to the (-) battery terminal.
Not all vehicles have a negative ground. Modern vehicles, yes. Dont forget that old vehicles, especially old british ( triumph) and german (VW) had positive ground. Also old ford farm tractors, like the ford 8n. Although, to the best of my knowledge, I believe most positive ground vehicles where 6v. Although vehicles arent true earth ground, a chassis ground is the next best thing, giving the electricity a path to the battery.
 

rednecktech00

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Aug 28, 2005
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Re: True Ground?

Just remember that whatever electricity comes out of the battery has to be returned to the Same battery.

You cannot complete a circuit on one battery by using the ground on another battery.
 

Silvertip

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Sep 22, 2003
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Re: True Ground?

Just remember that whatever electricity comes out of the battery has to be returned to the Same battery.

You cannot complete a circuit on one battery by using the ground on another battery.

Unless the two batteries are in parallel in which case you can.
 

UncleWillie

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Oct 18, 2011
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3,995
Re: True Ground?

Unless the two batteries are in parallel in which case you can.

At the risk of getting "Technical" ... :facepalm:
I would argue that Two Batteries in parallel, is/are One Battery! :)
And I understand that your statement was just for the sake of argument.

Considering that a "Battery" is a collection of "Cells" wired in common.
It does not matter whether the Cells are in the same case or not.


This is a single 2.1 volt cell.....
m70.JPG


And 24 of them in series make one 48 volt battery!

m72.jpg

Such is the construction of a 6000 Ah 48 volt Battery of Cells.

And there there are 10 racks of them in parallel, making a single 60,000 Ah, 48 Volt Battery.
That would make it a 2.9 MegaWatt-Hour battery if my math is correct.

m84.JPG

I thought you might appreciate the display on the front of the battery charger.
Yes, it shows 52.8 volts at 1483 Amps. And that's just the standby "Float" charge! :eek:
 

Silvertip

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Sep 22, 2003
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Re: True Ground?

We are certainly worked this one to death. Who would a thunk it would take 70 posts to figure out where ground is -- or what it is -- or why it is -- or when it is -- and if it is.
 

UncleWillie

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Oct 18, 2011
Messages
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Re: True Ground?

I was thinking the same thing. "Here We Go Again!" :D

I thought this thing died two weeks ago!

Wouldn't it make sense if threads self-locked if there was no activity for 10 days or such? :cool:
 

scrit9mm

Chief Petty Officer
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May 31, 2011
Messages
425
Re: True Ground?

I was thinking the same thing. "Here We Go Again!" :D

I thought this thing died two weeks ago!

Wouldn't it make sense if threads self-locked if there was no activity for 10 days or such? :cool:

I disagree! I have not corrected the issue yet. I have not had the time to get around to it. When I fix it I will post what the issue was and the remedy. That way if someone were to search for it they could see the outcome.
 

smokeonthewater

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Dec 3, 2009
Messages
9,838
Re: True Ground?

I think we all figured that you had it fixed and just didn't post back about it. If you DO end up needing more help please don't let our clowning around bug you......
 

JASinIL2006

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Feb 10, 2012
Messages
5,754
Re: True Ground?

Wow! I just read 4 pages of posts on wiring, electrical theory and germanium transistors, and the original problem still isn't fixed. I can't stand the suspense! I gotta know how this turns out! :D
 

MH Hawker

Vice Admiral
Joined
Jul 13, 2011
Messages
5,516
Re: True Ground?

Wow! I just read 4 pages of posts on wiring, electrical theory and germanium transistors, and the original problem still isn't fixed. I can't stand the suspense! I gotta know how this turns out!


Stick around it get worse lololol Its just the beginning of squirrell season.
 
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