Re: High-Power Car Ignition Coils

Hi Sam,

At 09:49 AM 12/29/98 -0800, you wrote:

SSSSSNNNNNNIIIIIIPPPPP>>>>>>>>>>>>>>>>>>>>>> :-)

>1- The halogen light gets EXTREMELY hot, and it is so bright it is
>giving me headaches. What would be a better substitute for it? I can’t
>really get 500Watts resistances and a string of 5 100Watts resistors
>would get pretty hot too. How about inductive ballasting? How could I
>use it for this device?

I would use a space heater or electric oven element instead of those super
bright lights.  You can use an inductor if the frequency is fixed and
constant.  Just adjust the reactance (Xl = 2 x pi x L x F) to the same
resistance value as your lights.  However this may not work depending on
what the signal really looks like...   Capcitors my not handle the current

>2- The insulation around the HV terminal is not enough to keep it from
>arcing to the primary terminal screws, which are just outside it. I am
>currently using insulation tape but it won’t be long before it breaks
>down too. Has anyone done anything like this before? Any ideas on how
>to insulate it better? Maybe some PVC pipes with epoxy?

Drop them into oil!  That's how I insulated the big 200 kV from the input
terminals in my GM coil.  Epoxy likes to crack and get bubbles unless you
are really good at it.  The oil should aid cooling too.  I would get
mineral oil or test regular auto type oils as an isulator.  The model plane
fuel sounds a little dangerous since sparks are like 10000 degrees C.  It
may explode or do something bad.  I think the car oils would be much
cheaper.  (I think this subject is from your other post today). 

>3- Has anyone tried ignition coil drivers before with good results? I
>am REALLY interested in your experiments. Anything. Like, what was the
>power level you ran your at and how did it behave. Has anyone got more
>than 10cm long arcs from it? I think I hold the record for highest
>power out of an ignition coil, but hey, I would be quite happy to be
>proven wrong!
>4-  How much power and voltage is a typical ignition coil really
>designed to work at? I now know it is more than 50 watts. Maybe 200?
>Does anyone know? What is the actual limit? Core saturation?
>Overheating? Insulation breakdown? I wonder if it would saturate
>before the power caused it to overheat… Unfortunately I don’t have my
>multimeter anymore:-( died while I was doing some tests on this device…

I found at 1700 volts input from a 1.7uF cap the GM coil wanted to die
really fast.  The ouput started to short internally at 200kV.  Heat and
saturation (I had no core) were not factors in my tests.  In oil, the
heating was zero.  I ran at low average power levels though...

> I haven’t posted the circuit yet because it is under construction. I
>have a word file with a full explanation of how it works and a parts
>list/circuit diagram. It is the full instructions for building it. If
>anyone is really desperate for some action I could mail it to you, but
>I would rather finish my testing first…

I am sure many people would be interested in this for their coils too...

> P.S. I know Terry has a GM high-power ignition coil to spark MUCH
>further than this device will ever be able to. 

You bet it can!  Don't even try to beat my record!! :-))


> Sam Barros

Great work your doing Sam!!  

BTW - My GM coil project is going slowly due to other stuff I am doing.  It
is still on my list however...