Joule Thief

[xee2]

@ jeanna

I would only try it with the 10T/60T you suggested. not the ig coil.

It is always better to be safe than sorry. But that spike is what you have been using in the JT. I do not want to suggest you do something that will cause harm and high voltages are much more likely to cause harm than low voltages. So perhaps you should not use the ignition coil. I was only trying to help because I thought you said you wanted to use an ignition coil.

[jeanna]

...I was only trying to help because I thought you said you wanted to use an ignition coil.

I appreciate it too.

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.

but in a joule thief the primary bifilar does not seem to be the best place for the spark. the secondary is rather safe for the transistor.
It is the spike that is what we are going for, yes, but the 450 volts are occurring on the secondary and blowing leds, but no transistor because it has a "magnetic layer" of protection.

So, if I were to use an ignition coil as the secondary off the joule thief, I would not want to ground it onto the battery because of that spike.

But then where?

But more than any other question, I am asking how the ignition coil can act as a high voltage transformer when the primary is electrically connected to the secondary.

thanks a lot,

jeanna

[Pirate88179]

Xee2:

I think I see what you are saying here.  The way I see your proposed circuit is not that much different than the Fuji circuit.  There is no danger to the 2n3904 on the modified Fuji even though the output is almost 400 volts.  In your circuit, as long as the 3055 does NOT get tied into the secondary, I don't see a problem with it blowing the transistor.  All that I see happening is that we are using the pulses from the JT to replace the pulses from the points normally used with that old style I. Coil.  I believe your circuit will work just fine.  One could also tie one of those into a Bedini motor and have the rotor derived pulses fire the coil.  Wow, a Bedini with a 30,000 volt output....now that sounds neat....and dangerous....but cool.

Bill

[jeanna]

An ignition coil is a transformer. A primary and secondary is needed in order to produce the high voltage,about 20kv,to fire the spark plugs. The collapse of the secondary magnetic field induces the high voltage. ...

Hi IotaYodi
I must have missed this post. I would have asked you rather than xee2 again, just now.

I am under the impression that a transformer is made of 2 separate wires coiled around a common core such that the wire of each is close to the other so the mag field of one can create the electric ?field? in the other... bla bla
AND they are not at all connected through the wires.

How, then can an ig coil be a transformer when the primary is wired to the secondary?

If I can understand this, then I think can proceed.

thank you,

jeanna

[xee2]

# Pirate88179

I think I see what you are saying here.

I think you got it Bill.