How an Ignition Coil Works!

Understanding this principle is key in being able to interpret ignition waveforms on a lab scope.
This clip was taken from my Chapter 1 Playlist on SD Premium where I'm introducing a group of new students on how an ignition coil can take 12v and make it 40,000 volts.
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For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.

[@richardstockwell4862]

Just passed a2-a8 in the past few days thanks to you paul! Keep up the great work!

[@ScannerDanner]

Fantastic!

[@jeffhesse8415]

1st three and a half minutes is priceless information, understanding voltage readings throughout the system is a huge time saver in diagnosing.

[@spelunkerd]

The concept that took me a long time to understand was how the direction of current in the secondary ignition wires has nothing to do with battery ground. Years ago, my naive self assumed that electrons would always travel from battery ground to the central positive pole across the plug. Not so. The coil generates about 10,000V+, it doesn't care about 12V, either way. The direction of current from a coil has everything to do with the relative direction of primary and secondary coil windings, clockwise or counterclockwise. Conventional current within the secondary windings of a coil does not seek out and travel to battery ground. It searches for and travels to the other end of the secondary coil. Many waste spark systems use flow that alternates current direction, and they work just fine.

[@bartscave]

Your secondary ignition scope video is excellent.

[@alexmessina3383]

Thanks. This comment helped me clarify in my mind some anomalies I've seen the past ... I had a Mazda2 once that had a negative fire pattern (COP not DI) ... I was confused, but it appears some systems are negatively fired. .... Question: Why is the Secondary of a conventional or COP coil connected (physically) to the primary pos side??

[@joeswampdawghenry]

@@alexmessina3383 because... Jus for fun... Lol? Idk

[@Official3an]

Becoming better tech studying these videos

[@scientist100]

Lol doge

[@davidhall3747]

Paul- you took a complex subject and simplified it. Thanks man!

[@nancylewis7142]

THANK YOU for what you do for all of US, again.

[@secondwindmusicproductions]

I use an analogy to help understand inductance that may benefit your students. I imagine the DC circuit to be a fluid system and an inductor to be a turbine in series with the fluid flow. Attached to the turbine is a flywheel. So when connected to the circuit as in this lesson, with the switch (in my analogy a valve is closed), the flywheel is stationary. When flow starts, the flywheel retards the flow proportional to its speed and it eventually attains its maximum speed for the pressure applied, ie, saturation. Now if the flow is suddenly stopped, it is pretty intuitive that the flywheel does not want to stop and the turbine now becomes a pump and drives the pressure (voltage) between the pump and valve very high. For the record, the music logo that appears here is my second career. I spent 40 years as a practicing engineer and engineering manager designing elecro-mechanical machines from the early 60's through to 2000. Much of the control of those machines was very similar to today's automobiles. Lots of sensors, a control unit and many magnets to instigate mechanical actions. I very much enjoy this channel and especially the debugging of problems by understanding how they work instead of throwing parts. Keep it up.

[@fredautos]

Thanks Mr. Paul. Your simply a teacher and a brave legend!

[@richardcranium5839]

a ford duraspark2 will put out 75k. i know i was watching the sun scope as i pulled wires and got bit. you never forget a bite like that!!!

[@0tt0z]

Thanks for sharing this with us! Great information. 👍

[@Pablo_Automotive]

Thanks again Paul 😊

[@ismailbayram336]

Thank you very much all of these informations.

[@robertmedina6875]

Great job, Caleb and Paul!❤

[@ozzman530]

Amazing content. Wish I could take these classes live and get hands on with an instructor like this at my side.

[@d.d4184]

If you are serious buy the book get sd premium and take the classes that go along with the book. This is your wish answered.

[@ozzman530]

@@d.d4184 I think you may have missed my point.

[@d.d4184]

@ozzman530 no I didn't miss your point. You are not going to get hands on with him. Book and classes is next best thing. Don't look for excuses.

[@ozzman530]

@@d.d4184 Hi thanks but please don't negate the content of my original comment by reinforcing the reality for an obvious rhetorical statement. What study methods work for you do not translate to everybody and your lack of understanding this concept is not an excuse. Books are not just not as efficient for some folks. Thus why I am on KZbin to begin with.

[@joeswampdawghenry]

@@ozzman530 bravo bravo!!!

[@isalmankhan1]

This is AWESOME👍🏻👍🏻👍🏻 Soo important lecture, Thanks for sharing SD👍🏻👍🏻👍🏻 These lectures deserve a Million likes😍 Stay Blessed SD🙏🏻

[@petersonbalavoirjeanbaptis7649]

I'm your student from Haiti

[@ScannerDanner]

Love this

[@lovemoremurasi7052]

Thank you so much ❤❤

[@hurls2301]

Great explanation. How does the primary circuit safely dissipate the 400v spike without frying the ecu?

[@ScannerDanner]

The transistors that control coil primary are very robust! Injector drivers will use a zener diode to dump off some of the spike, but with ignition coils you won't see that.

[@tibortorok6343]

Thanks for Hungary.perfect!👍

[@ScannerDanner]

Awesome! Thank you

[@coycarlson4979]

Those of us who are old enough 😳 to remember ignition circuit contact points ( POINTS ) which were literally a mechanical switch - which would open and close to fire the spark plugs. The high lobes on the distributer would open the contact points at each cylinder spark plug so the magnetic field which built up in the coil would collapse in / across the coil secondary winding and fire the spark plug.

[@teddymullins3706]

I have a dwell meter in by toolbox For small block and big block Chevrolet With old school mechanical points I haven't used it in years !

[@douglash3129]

Hi Paul, ground side switched, like points?

[@mauriziogiasan4411]

thanks😊top

[@douglash3129]

Moving magnet, lawnmower flywheel?

[@drivewasher]

I;m a big fan Paul, Great video, but it "sparked" thoughts in my head. Should the blue secondary winding be tethered to the 12 volt primary? I would have expected it to be on ground as that's where the spark will end up. Your drawing is correct, then you would get 12 volts on the "tower" when the control wire is not grounded. Sorry, I know when I think it's dangerous

[@ScannerDanner]

Yes, the secondary winding will be attached to coil +, ground, or another coil tower (waste spark)

[@user-yf7em4gh5i]

Sir Paul, where's the other end of the 2ndary coil attached? I notice on other diagram sir they attached to ground,and the principle of current flow always flowing on less resistance,it means their will be no current flow to coil tower due to high resistance on spark plug gap,..it will detour directly to ground where other end of that secondary coil attached...makes me confused

[@ScannerDanner]

It can be attached to either coil positive or directly to ground or on a waste spark coil the other spark plug! It's a return path for the secondary winding no matter where it is connected. It is strange, but that is how they work.

[@user-yf7em4gh5i]

@@ScannerDanner thank you sir Paul...hope you can maka a video that you explaining thoroughly that scenario sir....

[@ScannerDanner]

@@user-yf7em4gh5i I have them! But those classes are on my website

[@douglash3129]

I guess I spoke too soon Paul!

[@joeswampdawghenry]

So how much voltage did my coil shock my ass with when i touched it??🚨🚨🚨🚨 shuld i b dead??

[@ScannerDanner]

😂

[@richardnilsen5]

S.D. the Jesus Christ of auto diag Making blind people see you could ask for better but you would never get it ♦👍👃😁

[@ellieprice363]

Sorry, I need a lot more than squiggly lines to fully understand how coils work.

[@ScannerDanner]

Join my classes on my website. I can teach you! www.scannerdanner.com/join-scannerdanner-premium.html