Inside a Car Coil

[john_g]

Hi All

In many of our projects we are using car ignition coils for HV. I took one apart (car-coil-apart.jpg) and was surprised in my example just how small the coil was inside and also how poor/cheap was the way it was put together. Maybe we could get better with home made? Thinking about the size of the old induction coils.

In my example to take the HV from the secondary (coil-pu.jpg), a brass plate is pushed against the core (multiple plate laminates not filling the core very well) and then a spring from the end of the plates pushed against the HT terminal, must be some loss here?

Regards

John

[Bodkins]

Thats just crap for build quailty.Im going to try this with one of my Icoils.

[wpage]

Cheezy coil

That is a poor looking quality. Whos is it.?

What year?

[john_g]

That is a poor looking quality. Whos is it.?

What year?

It was made by Motorcraft (England) I suspect in the 1970s.

[slayer007]

When you take it apart can you see the four wire ends.
I can see the primary ends in the picture but not the secondary.
Are you able to get to the secondary winding ends.

I was just thinking it would be a cheap and EASY way of using a coil in my pulse generator.

[john_g]

When you take it apart can you see the four wire ends.
I can see the primary ends in the picture but not the secondary.
Are you able to get to the secondary winding ends.

I was just thinking it would be a cheap and EASY way of using a coil in my pulse generator.

Yes you can. As you say, the 2 primarys are obvious. I have seperated out the secondary windings - one end was attached via a crimp to one of the primary ends, the other end of the secondary is attached to the small brass plate within the core hole (picture on first posting). I have seperated the wires and soldered on wires to enable me to pick up the secondary as a seperate circuit.

[slayer007]

Yes you can. As you say, the 2 primarys are obvious. I have seperated out the secondary windings - one end was attached via a crimp to one of the primary ends, the other end of the secondary is attached to the small brass plate within the core hole (picture on first posting). I have seperated the wires and soldered on wires to enable me to pick up the secondary as a seperate circuit.

Thanks john_g for the reply.
I'll have to take apart one of the ignition coils I have and give it a try.

Thanks

[BinzerBob]

Notice that the coil is put in a wax substance. This is done I would imagine to help with insulation because of the high voltage? I thought that the coil would have been filled with oil, but I guess the wax does a good job.

[john_g]

Notice that the coil is put in a wax substance. This is done I would imagine to help with insulation because of the high voltage? I thought that the coil would have been filled with oil, but I guess the wax does a good job.

BinzerBob

Sorry, I should have said in my first post that the coil was oil filled.

Regards

John

[chemelec]

BinzerBob

Sorry, I should have said in my first post that the coil was oil filled.

Regards

John

Most Ignition Coils are Oil Filled.
Oil Creates a "Self Healing" effect.
If the coil creates a Short because of an Internal Arc, The Oil usually Flows back over that area to stop the arcing.

So Oil is Superior to Wax.

Some of the Newer Coils are just Potted in Epoy.
When they Short out, There Dead forever.

[Vortex]

DIY Ignition coil?

Lindsay's Technical Archive: Gingery Buzz Box

Model-T Ford ignition coil but it is actually a home-built version, using readily available modern materials.