In A DC circuit current flows from - to+. In a auto it makes no differance neg ground is the standard.
Evidently there are A/C and D/C clouds. That's why some have "Things" sticking out on them and others don't. And don't ask me where cause it depends. Anyhoo, if lightning hits an airplane and it's not grounded, then does the charge come FROM the airplane or from the clouds? Lets suppose your T-50 is neg ground. Your flying along trimmed out and half asleep. Now a bolt of lightning hits #1 engine from a positive ground D/C cloud. Since the bolt is D/C will it just charge your batteries. Or, will it mess with the magneto's and cause the Cessna to go nose up and spin to the tarmac. I'm betting you'll be home for supper. Lippy
Hmm, if it's D/C positive ground, then if my battery is low, I can draw from the fender if I need it for emergencies? Oh, I see now nevermind.
This is starting to remind me of this thread..... http://www.jalopyjournal.com/forum/showthread.php?t=318355
Oh shit,,, 4 pages? is everyone freaking crazy? It is simple, nevermind the inconsequential technicalities of WHY neg ground or pos ground, none of that matters, everyone eventually picked a COMMON direction for economic reasons, damn the science, the science of the decision was too small to effect a change, $$$ made the change. The difference is the difference between Coke and Pepsi, and most people DON'T GIVE A SHIT... only "some people" care.
Maybe it has been said, the reason they later changed to negative ground was the fact that elecrons go out negatively... oxidation vs reduction ... chemestry.... it is a small way of rust controll... keeping it negatively charged helps it keep electrons instead of taking away... kind of like using baking soda, water, and a tricle charger to remove rust..
You've got the first part backwards. Skin effect is an AC phenomenon caused by eddy currents created by inductive reactance. By definition, reactance only occurs in AC and there is no skin effect with DC. The audio people have been selling the myth of more strands is better for a long time, but the truth is that skin effect does not even manifest in AC until frequencies reach far beyond the range of audio frequencies. At 60hz in copper wire, the skin depth is about .33 inches. You would have to be using 0 gauge wire before any of the conductor became unused due to skin effect. As a degreed and licensed Electronics Engineer, I have to say that there is a lot of misinformation in this thread. None of this shit matters if you simply observe the established polarity.
No. Not even close. The same current flows through the ground wire as the positive. I hope that is what the big smiley face is about, especially considering your name. Okay, after reading more of the thread it is obvious this was tongue in cheek. Sorry.
This has been settled for a LONG time. Negatively charged electrons flow from the negative to positive meaning that negative current flows from negative to positive. Mathmatically it is the same as positive current flowing from the positive to the negative so by convention that is how it is treated.
I'm not sure if they knew that then, but yes we have a winner!! it does make a big difference in how efficient a spark plug works on which way the current flows, tip to ground or ground to tip. one side of that giant alternator at the power plant is connected to earth, that's how that works, it acts like a big conductor back to the source. as far as the time travel, you need a flux capacitor, and that's nuclear powered,which starts an entire new argument. you can have ground to cloud, cloud to ground, cloud to cloud, and all kinds of really freaky weird stuff they are now finding. the ground to cloud is a heck of a lot more powerful then anything else, they are finding sprites appearing hundreds of miles away whenever a ground to cloud strike appears, they were finally able to photograph them from space. No one is sure what they are, my guess is some sort of plasma, you have extremely high voltages and unimaginable currents occurring in an ionized atmosphere with a magnetic field , strange things are going to happen. http://www.youtube.com/watch?v=1xVThAFfP0E all right start the jokes, it was called a vibrator, it would change the low voltage DC into the pulsating DC needed to make the transformers work. I'm into old radios. If you ever mention that to anyone you get a look like you just said a dirty word. it depends. MOST of the time the airplane is ok, if it happens to end up being the conductor between cloud A and cloud B, very bad things can happen. the other thing to remember, is the electromagnetic pulse from the strike can do very serious damage to the electronics. they are built for it, but nothing man has made yet can protect against everything. There is a lot of study going on about ground to cloud lightning too, much more powerful strike, and a lot of people believe it may be the result of a number of unexplained crashes over the years.
I believe swapping the two primary wires on the coil will affect which way the spark jumps? Like the guy said above,none of this matters on older stuff with no solid state devices.So long as the engine starts,runs smooth,the amp gauge needle moves in the right direction,you're good to go.
well the high voltage leaving the coil has to jump to something, it's DC so it has a positive or a negative, if the ground on the car is one way, it will jump from the center electrode to the ground, if the other way it will jump from the ground to the center electrode. to clear it up for anyone, the high voltage in the coil isn't created from adding voltage, it's from taking it away, it's a big coil with a primary and a secondary winding, the secondary winding has a lot more turns then the primary, since it's an inductor, taking away the primary voltage(12 volts or 6 volts) the magnetic field that was in the coil collapses, and this field induces a large voltage in the secondary coil which causes the spark to jump the gap at the plug. A lot of people think adding voltage causes the spark. all adding voltage does is build the initial magnetic field.
Did you ever see the picture in old repair manuals of a pencil being held between the plug wire and the spark plug terminal? It's to determine polarity depending on which side of the pencil the spark jumps.
While we are WAY off the subject, I have a question involving something DDCoopman said about spark plugs. Has anyone heard of "waste spark" ignition in new cars? Anyone explain it? I have been told how it works, just want to check it against the braintrust here on the HAMB. It's pretty cool actually.
Very few people are aware that when Dr. Brewster M. Higley penned the words to his famous poem that he would be so widely misquoted...
"It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination."
Keeping the aforementioned in mind, and specifically talking about a "deranged imagination", you ain't met my mother-in-law yet. DD
Vibrator! That's the term I was looking for. Everybody knows that. I haven't heard of anyone mentioning a vibrator in a tube radio for such a long time, I forgot the correct word. A vibrator is what creates pulsating DC current to make a transformer work. Why did I forget that for a moment?
Yes, you are correct. The direction of the spark has nothing to do with the car being positive or negative ground. It has everything to do with the polarity (conenctions) of the coil. The coil is an autotransformer. If you hook up the primary (12 volt) wires to the coil backwards, the spark at the plugs goes the other way. Old timers like me would diagnose a 'backwards' hooked up coil by opening the plug gap and holding the tip of a lead pencil in between the electrodes. If the spark went from the center electrode to the pencil lead meant one thing, and the spark going from the outer electrode to the pencil tip meant another. Of course, as an old timer, I no longer remember which was which. LOL Now, by cracky, all you young whippersnappers get of'n my lawn.
It just means the plugs fire every time the piston rises instead of every other time. You save parts and programming.
Yes, but the explanation I got was the sparkplug under compression fires from the electrode to ground and the opposing cylinder fires from ground to electrode to clean the plug. Isthat how you understand it?
No, that is not the case. It is just twice as many sparks due to timing trigger events to the crankshaft instead of the camshaft. There is no change of direction.
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