primary ignition principle

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primary ignition principle

Postby Willem » Fri Aug 06, 2010 5:46 pm

Hello technicians,

There's a thing I never understood when I comes to the primary ignition waveform. Where does the burnline come from? In secondary it makes sence to me, but in primary the current is just being grounded by the ignition module isn't it?
Or am I thinking in the wrong direction?
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Re: primary ignition principle

Postby Matt Fanslow » Fri Aug 06, 2010 6:24 pm

You seem to be forgetting that the control side of the primary has to be released before the magnetic field can collapse.

HTH. Later, Matt.
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Re: primary ignition principle

Postby Willem » Fri Aug 06, 2010 9:05 pm

Hi Matt,

Thanks for your reply, I understand the part your talking about.
When the earth is removed (by the ignition module) it induces a certain voltage trough the primary coil. What I don't get is the burnline wich is caused by the spark jumping over the sparkplug gap, BUT there aren't any sparkplugs in the primary circuit.

I feel a bit dumb for asking, but I just don't see what I'm missing here. I hope you understand what I mean, because I didn't pay much attention when I was in english class.
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Re: primary ignition principle

Postby Matt Fanslow » Fri Aug 06, 2010 10:27 pm

Right, the collapsing magnetic field induces voltage in the primary, as well as the secondary.

We basically see a reflection of what is happening in the primary in the secondary as well as a reflection of the secondary in the primary, depending on the part of the pattern we discuss. In your example we are seeing a reflection of the secondary in the primary.

Maybe one way to think about it is that they both are dissipating the same magnetic field.

HTH. Later, Matt.
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Re: primary ignition principle

Postby Dave Hill » Sat Aug 07, 2010 5:52 am

Nice description Matt.

I am in the process of putting another article together, that covers this topic, for the "Everyday Diagnostic" section of the Pico site.

Ignition primary & secondary can be very confusing. When I started scoping & I had similar questions to those of Willem. The scope really does help you understand electrical processes that were previously just a fog in the mind (That's the way I felt anyway :? )

A good question Willem! Keep an eye out for my article. I think it will raise more questions like the one you asked.

Regards

Dave Hill
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Re: primary ignition principle

Postby Willem » Sat Aug 07, 2010 11:51 pm

Thanks Matt for the explanation, this is vert. Helpfull.
And Dave I am looking forward to your article.

Greetz...
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