A Dissected Ignition Coil

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KitCarlson

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I have a project where I need core laminations from an ignition coil. I started with a coil I found in my coil box that was leaking oil from the tower. What was inside is worth sharing with pictures. I made a cut around the top rolled edge to open it. It was nearly full of light oil, that was difficult to wipe off surfaces, it just kept coming back.

Here are the parts pulled out of the can:View attachment 20150901_141253.jpg
At the upper left is coil can, under that are two half cylinder shields, then a brown paper insulator. The coil/core assembly is on the right. The outer coil is part the primary, it is formed of multiple winding sections, each separated with paper insulators. There is a second group of windings for the secondary inside the primary bobbin. The secondary windings are done using smaller diameter wire, with more layers, so the number of turns is about 100 times that of the primary.

This is an end view showing the winding construction. The square metal part is the core laminations.
View attachment 20150901_141535.jpg


The core conducts the tower potential, it is insulated from the bottom of can with a white ceramic insulator shown in the top photo. The insulator also serves to locate the bobbins in the can. The outer side core laminations were bent sightly, to make a mechanical connection to a leaf contact on internal tower. The coil+ terminal is the common connection, for the primary to secondary auto-transformer.
View attachment 20150901_141941.jpg View attachment 20150901_141647.jpg

One of the most common coil failures is a turn to turn short in a primary winding. The enamel insulation on the copper wire serves as the insulator. If winding is overheated the enamel burns, a shorted turn consumes a huge amount of current resulting in failure of normal coil operation.
 
Mechanically / electrically, at least physically, not much to 'em. Frankly, when you add up all the gasoline powered cars and trucks over the years, and the relatively few that has failed, pretty reliable.
 
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Coils are a disposable part when they begin leaking or are burnt up.
Same goes for ignition control box's, electronic voltage regulators and ballast resistors.
Non rebuildable.
Keep spares of these items to swap out when needed and don't bother yourself with the mess of taking them apart.
Does seems a waste though, they should have made the parts more serviceable like in earlier
days. 40s and 50s cars were not built with so many disposable parts.
 
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Coils are a disposable part when they begin leaking or are burnt up.
Same goes for ignition control box's, electronic voltage regulators and ballast resistors.
Non rebuildable.
Keep spares of these items to swap out when needed and don't bother yourself with the mess of taking them apart.
Does seems a waste though, they should have made the parts more serviceable like in earlier
days. 40s and 50s cars were not built with so many disposable parts.

I don't think you get it. Dave is using the core material for some experiments he is doing. I have no idea the depths of what he does and knows but it goes far beyond me.
 
Mechanically / electrically, at least physically, not much to 'em. Frankly, when you add up all the gasoline powered cars and trucks over the years, and the relatively few that has failed, pretty reliable.

That is very true! I have only encountered one leaker, and one with red spark, in my 44 years of experience on my numerous cars and other vehicles.
 
Not to rain on your parade but the early type coils. Into the 70s these were filled with pcb laced oil just like big transformers.
 
Ahhh, I see. Thought it was a repair. Not the first time I didn't get it.
 
About the core, I am going to experiment with electric paintless dent removal. It is a diy project, it might be driven by a high voltage supply and micro controller.
 
Can we ask which parts of this coil are being salvaged and what its new intended use happens to be?
And what's a pcb?
 
Mechanically / electrically, at least physically, not much to 'em. Frankly, when you add up all the gasoline powered cars and trucks over the years, and the relatively few that has failed, pretty reliable.

I would change that to very reliable.
 
I knew that, and skipped using it to fry my french fries.

LOL, I've probably got enough old military filter caps in the basement to kill half the neighborhood. I used to "piddle" in amateur (and legal, not CB) linear amplifiers. I've forgotten, old Swan pair of 3-400's, Heathkit, pair of 3-500Zs, a homebrew with 4-1000A, a nice little military with 3 4cx-250Bs, a homebrew 8877, an old Hallicrafters converted to 813s, and a Drake along the way. Probably a couple more I've forgotten. These days, a single 3-500z, in an Ameritron. Oh, and a Transworld / Metron 1000 something solid state mobile amp. Parts and pieces I'll never use.

And I'll tell ya, with that kind 'o stuff, you don't LEARN to be careful, you just plain BE careful. No second chances. Some of them are 240V AC supply, and the 4x1 ran something on the order of 4KV on the anode. Some of the rest were a "mere" 2500-3KV on the plates.
 
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