Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>
Rich,
I don't think modern ignition coils quite work like that.
The old "T-Model" coils had their own points/capacitor
and were essentially an induction coil that functioned
quite well with a 6 or 12 volt DC input. However, a modern
ignition coil is essentially an impulse transformer that re-
quires a pulsed input of several hundred volts amplitude to operate
properly, which is provided externally by the ignition
control module. A simple 12 volt DC input will not not yield a
usable high voltage output from an ignition coil. You can simply
apply 120 volts AC through a small (< 10 uFD) run
capactior seriesed with a soild state dimmer switch to an
ignition coil and get a usable pulsed HV output.
David Rieben
----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Monday, September 05, 2005 8:14 AM
Subject: Re: Beginer building a small sstc.
Original poster: Rich Simpson <richcreations@xxxxxxxxx>
Hi Nick,
I suggest using an automotive ignition coil instead of a flyback, and
a 3v trans is not insulated well enough. Ignition coils are cheap or
free, and do not have output diodes. they do put out more then 10kv
with 12v input, but a lower input voltage, would fix that.
-Rich
On Sep 4, 2005, at 4:33 PM, Tesla list wrote:
Original poster: "Nick D." <ngdbud@xxxxxxxxx>
I am 14 and have a few questions about a small Tesla coil I'm
trying to build. First of all, the dimensions for the secondary
coil will be 2.5 inches in diameter and 10 inches tall. I have a
homemade plate stack capacitor that can handle 10 kv playing on the
safe side. I measured it to have a capacity of 26 nf ut under my
body weight I can get it up to 40 nf. For a coil this small I'll
probably leave it uncompressed. As for the power supply, I would
like to stay away from wall sockets and work off battery power. I'm
thinking of using a squre wave generator sending out pulses at
1-100 khz at 10-15 volts and running it backwards through a 3 volt
transformer, this should get me between 4 and 6 kv. My second best
choice for power supply would be a flyback transformer, but I only
have the newer types, encased with plastic and having cylindrical
secondar coils. I made a torid for the coil out of three feet of
dryer hose. it has a 9 inch diam eter and is 4.5 inches tall. Is
this too big for my coil? Since I'm working at this low a power
level, I plan on using 18 awg speaker wire for a primary coil and
28 awg for the secandary. Is 18 awg too thin? For the primary how
many coils should I use and how far apart should I space them? If
you have any comments or answers to even just one question, I would
love to hear them.