Joule Thief

[electricme]

@Jeanna,

Thank you IotaYodi,

You know that is what I thought it was. Someone posted the pic I will post below so you and anyone else who is interested can see what was so confusing.

jeanna

Hmmm if you knew what you thought it was, then you wouldn't have been so confused all the pages back asking those questions, what was so confusing about it.

What IotaYodi said, is correct, but he didn't go far enough with his answer.


The ignition coil is designed for either a 6v DC or a 12v DC electrical system.
If you want to power any ignition coil from a joule thief, then you need to reduce the JT output to a manageable level to do this.

The JT output is now at wavelengths of HF voltage/frequency, at micro amps.

The Ignition coil cannot work correctly on frequency levels as its input voltage.
It needs a steady DC which is interrupted at the points.

In actual fact, a DC is applied directly to the ignition coil, all the time, (in the kettering system), then the output (LO voltage out) proceeds to the ignition points, where the "lobe" on the cam then switches the ignition points to earth, this completes the circuit. The DWEL is the amount of "time" the coil is in charge. The dwel is adjusted by setting the point "gap", the "advance" or "retard" is the rotation of the firing position, relating to Top Dead Center".

If you were using a HHO system, then you need to retard the firing point to at least 10 degrese after TDC or you will get bent conrods.

Now the coil becomes energised, the magnetic field is formed.
The cam is rotating on its shaft, it lifts the ignition point to open, the magnetic field now collapses, a extreamly high EMF is formed, and the result is the huge spark we are all familiar with at the spark plug.

The KEY to making the JT work with a ignition coil is therefore to convert the vhv frequency of the JT output, back down to a much lower level of direct DC at amp levels. You will need to look at Frequency to DC converter circuits.
Then you will have success running a ignition coil from a joule thief.

When the ignition point opens it creates a extreamly sharp square wave.
The condensor makes the spark "flare" to ignite the petrol vapor in the cylinders.

IGBT transistors now seem to be the transistor of choice to do this, instead of the old mechanical ignition points, a Hall effect transistor triggers the TR by a "reluctor" (just a round iron disk with iron lobes (sharp points)).
It is configured basicly like a darlington/tripple darlington circuit.

If 12v is a little too difficult to make, try a 6v ignition coil from a motorbike.

If you want to use a scavenged HVF transformer out of a TV or PC monitor, get a circuit and study it, look for the section that drives the thing, or ring a TV repair tech, ask them how it works, what voltage and current it needs to produce the pulces.

Another way to do this is to take a look at how the ignition magneto on a lawn mower works, take bits of both circuits and see if that will work.
The lawnmower coil is much smaller, has fewer components, is trigered by the position of a magnet, ""similar"" to the working of the Bedini principle.

jim

[jeanna]

You know jim,
I appreciate that you went into all that detail about the ig coil,
but not one person including you, including iotayodi  has to the present moment answered my very simple question.
Iota Yodi provided a picture, but he did not answer my question either.

period.

I will not repeat the question.
I made it clear.

so thanks but yaknow, a person gets tired of asking the same question over and over.

jeanna

edit add,
@Gary

Then I tried connecting   it using  one  primary  terminal  and  the  secondary tower

Did you happen to notice if the primary terminal was the one that also had the secondary connected to it?

That would have made a loop out of the secondary. I wonder if that is the trick.
Thanks for that information.

j

[innovation_station]

well i got to talking to a friend today ...  he had some scrap copper hanging around ... lol

so i got a peace  it is called TEC 90 cable  ... 




it has a ground wire 3 sheilded wires and alum conduit it is rated 1000v 90 amp 

now thats a jt!! 

i will do some tpu expairmentes with it at some point ..  they use it on the XM2  as i hear ...

this will be used with my high freq rectifier and my 3 phase realys and a freq genny    probally only start with 12dc batteries for now and some caps ..   

i wasent gonna take a pic but i will and i love the ign coil design ...  aaaahhhh  its so otto tpu test lol

ist!

[electricme]

@ Jeanna,
ha ha, I think I got flammed, he he,,,,,

Is this your question?

My question was about how the primary and secondary are connected inside the ignition coil.
It seems like one coil; a bifilar in a way.

jeanna

No, it is not a bifilar wound coil.

The ignition coil consists of 2 seperatly wound coils.

The Primary is wound on the laminated iron former first.
The secondary is wound over the primary, and on top of the primary.

The end of the primary is connected to the end of the secondary internally, this is the earth connection.


Try this ere link  http://www.geocities.com/capecanaveral/lab/5322/coildrv.htm

someone is driving a ignition coil using 12v battery, a 555 timer and a transistor, he makes reference to toroid and a tesla.

The best one so far I have seen is Mad Teddies, here
  http://www.madteddy.com/igncoil.htm now this looks real interresting.

jim

Circuit below is curtesy of Mad Teddies, its a beauty.

[jeanna]

@ Jeanna,
ha ha, I think I got flammed, he he,,,,,

Is this your question?
Quote from: jeanna on Today at 05:41:48 PM

    My question was about how the primary and secondary are connected inside the ignition coil.
    It seems like one coil; a bifilar in a way.

    jeanna

Yes, thank you. It is.

No, it is not a bifilar wound coil.
...
The end of the primary is connected to the end of the secondary internally, this is the earth connection.

OK so, now I can twist together the 2 wires of the joule thief primary and put them both into the pos rail of the breadboard, and it IS a bifilar wind because of that,

yet,

if the end of the primary of an induction coil is connected to the end of the secondary and they both connect to the pos of the car battery (in that diagram it was the pos) that somehow takes it out of a bifilar and allows it to act as a transformer with all that this word implies.

Yes, this is exactly my question.
IF they are electrically connected, then they are acting just the way the joule thief primary bifilar wires are acting.
(which is NOT a transformer)

thank you,

jeanna