Re: mini tesla form ignition coil

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Sean Taylor" <sstaylor@xxxxxxxxx>

Adriano,

With an ignition coil from a car, you have to drive it with a high
frequency square wave (or at least have the current drop quickly) as
you have found.  Because of this, the secondary voltage is a high
frequency and won't work well to charge a cap as typially you need at
least one spark gap firing every cycle - kinda hard at 10 kHz or
higher.  Instead, you should rectify the output with some ultrafast
diodes.  I use SF1600's that you can get from Newark (though they
appear to be out of stock right now!).  The DC output can then be used
to charge the tank cap.  The charging current (thus charging
frequency) will determine the breakrate of the coil along with the gap
spacing and tank cap size.

Sean Taylor
Urbana, IL


On 3/6/06, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: "Dr. Adriano Mollica" <adriano.mollica@xxxxxxxxxxx>
>
> hello list,
>
> due the scarce portability of my first coil, i thought to build a second
> coil, very little.
> I didn't found on internet any plans for  a non-solid state small coil.
> So i turn out with a  idea: use a ignition car coil as HV source.
> So i took the i. coil and i applyed a alternate voltage form a 16v
> transformer, just to see the ratio. 240 v came out  .
>
> Then i realized that it wasn't enoght at all, and on internet i found
> another way to make it working...that is: 12v from a car battery, and a
> swich, that open and close very fast the circuit on the primary. So i did.
> and it came out a nice 1 inch spark from the secondary.
>
> Not too bad. It can also light up a small neon tube.  But, now, the problem.
> How can i use this source to drive a tesla coil?
> I tried to use this source as a HV transformer...but nothing happen. i think
> also that i actually don't know which is the output voltage of the circuits.
>
> any ideas?
>
> thanks, Adriano
>
>
>