Positive Ground

[Tom Endy]

Originally Posted by Crankster

Ignition coil polarity. This is a different matter and strangely enough, it has nothing to do with whether a car is positive or negative ground. The coil will work when connected either way, but the spark output at the plugs will be attenuated by about 25% if not hooked up correctly. Electrons "like" to jump from a hot surface to a cold surface, so the strike voltage required to initiate a spark is lower. There are a couple easy methods to check for correct ignition coil connections regardless of the markings on the coil itself, or whether engine is (or was) positive or negative ground.

https://mgaguru.com/mgtech/ignition/ig104.htm

When I was in high school back in the days of iron ships and wooden men our auto shop teacher, Mr. White, demonstrated how to tell the polarity hook up of the coil with a lead pencil. You insert the tip of the pencil into the spark stream and the direction it flashed tells you if it is correct or not. Then he would hand the pencil to the class clown to try it and watch how he would get a high voltage shock.

Today you can buy a device from any of the suppliers that hooks to the coil and an LED will tell you if it is correct. I bought one years ago and at a club event we tested about 20 cars. About half were incorrect and the owners were not aware of it.

Tom Endy

[Crankster]

Originally Posted by rotorwrench

Back in the day, they marked coil terminals with abbreviations for "switch" and "distributor" so that folks knew how to connect them. After the change from positive ground to negative ground they started marking then + or -. This is confusing to some when using a modern coil in an old positive ground system. To further confuse things, some coil manufacturers get the markings wrong.

Or an old coil in a modern system, or .. Yeah, I was going to mention this but you explained it way better than I ever could.

Just check it with analog voltmeter and reverse the primary coil wires if necessary. I think Jim Linder at Bubba's Ignition services or somebody said something about an ignition coil being permanently damaged by this defect, if ran for a long time, as the iron core is magnetized? Something like that. I like the neon or LED tester idea, should be easy to make one.

[J Franklin]

Originally Posted by woofa.express

I had hoped I’d learn from this thread but have ended up quite confused. I have concluded with-
1. I no longer care and
2. What does it matter.

I agree, if someone doesn't like the polarity they have, change it. There is too much polarity in the world now anyway.

[nkaminar]

Most lightening is produced when the ground is negative and the clouds positive, so the electrons travel up from the ground. Tell that to Thor next time he tosses down a thunder bolt.

The latest theory about everything is that matter is just forms of fragments of energy. These fragments are long strings that flow through the universe. The math behind this theory has shown to calculate gravity according to general relativity and how particles behave according to quantum mechanics.

[rotorwrench]

Lightening is a form of static discharge energy which has it's own rules with energy levels high in the megajoules. It has no conductor but can make ion pathways that allow for the discharge to move any way it wants to. The potential energy is way off normal electrical scales.

A coil works with half wave DC current so it shouldn't have any effect on magnetization similar to AC current. With the power applied to a completed coil circuit, it will build a magnetic field in the core if it is connected either way but the pathway to the breaker points is important to get the most efficient reversal of the magnetic field when the circuit is broken. The reverse flow has to take a very long pathway to create a discharge of high energy. This link has a good coil diagram so you can see the normal pathway.
https://mgaguru.com/mgtech/ignition/ig108.htm

In the Magnaflux inspection procedures, DC current is used to magnetize steel parts for inspection. It takes a lot of amperage to magnetize a part. Coil shots give a lengthwise gauss field and straight through head shots give circular gauss field in a steel part. After magnetization, the steel parts are slowly passed through a big AC coil to demagnetize the parts. Complicated shapes sometimes take a few passes through the AC coil but it will remove all magnetism from the parts. AC has a full wave current flow with constant reversal of the polarity. DC can only be manipulated to half wave to make a polarity reversal as in ignition coil, horn vibrator, and radio vibrator circuits.

[Crankster]

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Yeah, I was going to mention that, instead of power being generated in the coil by the relative motion of conductors and fluxes, it is produced by the modial interaction of magneto-reluctance and capacitive diractance. The coil primary winding was of the normal lotus-o-delta type placed in panendermic semi-boloid slots of the core, with every seventh conductor being connected by a non-reversible tremie pipe to the differential girdle spring on the “up” end of the grammeters. Simple, really.

[Jemelton#]

Smoke don't care! You let the smoke out, and the beast won't work. Keep the smoke in!

[katy]

Originally Posted by Crankster

Yeah, I was going to mention that, instead of power being generated in the coil by the relative motion of conductors and fluxes, it is produced by the modial interaction of magneto-reluctance and capacitive diractance. The coil primary winding was of the normal lotus-o-delta type placed in panendermic semi-boloid slots of the core, with every seventh conductor being connected by a non-reversible tremie pipe to the differential girdle spring on the “up” end of the grammeters. Simple, really.

That makes sense, I never thought of it that way.

[nkaminar]

rotorwrench, Doesn't the capacitor and coil set up a resonance ringing that causes multiple sparks at the spark plugs, in a really short time. The first spark is the big one, of course.

[rotorwrench]

The condenser catches the back flow from the reversal of the magnetic field when the points open and does have a bleed off that delays the complete induction process so it does keep the spark discharge going for a very short period of time. The scope illustrates that effect.

The condenser or capacitor is sized to match up with the resonance of the inductor coil so that the cycle will be as efficient as possible. The resonance is like the ring of a bell when struck.

The back flow of energy would jump the open breaker points if the condenser was not in the circuit to catch it which would quickly ruin the points and reduce the spark discharge to near nothing.

[Crankster]

The way it was explained to me years ago, the condenser acts as a kind of "shock absorber" and ensures most of the energy occurs between the plug electrodes where we want it, instead of arcing at the points.

I've seen in some of the forums people say they've been able to run a motor without a condenser installed for whatever reason. I don't think they are lying, so I wonder how that works. Theoretically it shouldn't run at all without a condenser? I'm sure it didn't run very well.

[Bob Johnson]

Boy there is a lot of interesting explanations here.


One of the reasons for using negative ground is corrosion. Many people use electrolysis to remove rust from iron or steel parts. The part is connected to the negative wire and a sacrifice piece of iron is connected to the positive wire. Rust is removed from the part connected to the negative wire and the sacrifice piece becomes rusty. A positive ground vehicle will rust much faster than a negative ground one.



I did my Master Thesis on proton conductivity. This is a rare phenomenon. It only occurs is certain crystals with loosely held protons. By definition protons have a positive charge. They do not transfer their charge. We use the term electricity because it is the movement of electrons. The electrons move from the negative source to the positive.



Bob

[Crankster]

Originally Posted by Bob Johnson

A positive ground vehicle will rust much faster than a negative ground one.

Sounds like just the thing, if you're selling new cars! That's why I'm skeptical ... lol

[Bill Cilker]

This question has been asked for a long time.
Here is an article on it from the August of 1931 Automobile Digest.

[TomInCologne]

Originally Posted by Crankster

Sounds like just the thing, if you're selling new cars! That's why I'm skeptical ... lol

But it does make sense when you think about it... in a corrosion process, the metal will pass its electrons to the oxyidiser, which will gladly accept it. If you have a negative ground system, the metal will find an abundance of electrons and therefore cannot pass its electrons to 'whoever'. But i agree that this effect may be miniscule...

[nkaminar]

Bill, good research. Thanks. I guess this is a good argument for using electrical grease to protect the cables and connectors. I see the auto parts stores have different grease and pads for the negative and positive sides of the battery.