Marshall; Like it or not, it is you who are incorrect. I would refer you
to any Motors Manual or Chilton's for a description of the standard and the
transistorized or capacitive discharge systems of auto ignition. For a
good textbook on the subject I'd recommend The Automobile Electrical System
2nd Ed. by Barr, Randolph R. and Thomas D. Flocco. Chilton Book Company;
Radnor, PA.
Short form: In the conventional or breaker-point ignition system the
primary voltage generated by the rapid collapse of the primary winding's
magnetic field is approximately 200 to 300 volts; this collapse is
considerably more rapid than the originating field buildup, hence the
higher voltage. The ignition coil is a transformer of approximately 100 to
1 turns ratio, thus 20,000 to 30,000 volts is induced in the secondary
winding, which is more than sufficient to produce a spark at the spark
plug. Under normal conditions of rapid cycling of this system to supply
ignition, and the generation of considerable heat in the coil and under the
hood, the system was just about at it's upper functional limit. The
Transistorized and/or "capacitive discharge" systems were a sorely needed
improvement which relieved the distributor points of massive intermittent
loads and arcing due to back EMF, leaving them the much easier duty of
signalling a transistor or SCR to turn on and off the current to the coil's
primary winding. This they could do even more rapidly than the opening
points did, producing higher primary collapse voltages up to
350. Eventually points were replaced entirely by optical or magnetic
signalling devices which didn't wear - thus the 50,000 mile tuneup and
considerably more accurate and competent ignition.
There are no automotive ignition systems running 50,000 to 100,000 volts;
not only is there no need for such a dangerous level, the corona discharge
initiated by such would be extremely and rapidly destructive to the
elements of the system, make the design of a distribution system for the
spark considerably larger, more difficult and expensive, generate a great
deal more RF interference, and be an absolute bear to keep functional in
damp weather.
The systems described did not rely on "leakage inductance"; perhaps you
meant to say mutual-inductance and self-inductance. Leakage inductance is
undesirable transfer out of the system of energy which escapes to the
surrounding environment, degrading both the system and the
environment. Leakage inductance does not contribute much at all to the
'time constant' in a decently designed system except by a tiny lowering of
the circuit "Q"; the self-inductance of the primary winding retarded both
its field buildup and collapse, and generated the 'back-EMF' that caused
the points to arc and wear rapidly. One role of the condenser placed
across the points was to absorb enough of this back EMF peak to discourage
such arcing; another was to provide a resonant tank for multiple spark
discharge (aka MSD,) in certain newer designs.
Take care, Malcolm
At 01:31 PM 10/26/03 -0500, you wrote:
Malcolm Stebbins wrote:
Oh Boy!! that's going to be quite a hit! The coil gets 12 volts from
the ignition system, and generates perhaps 200 + volts on "break" due to
inductive kickback or field collapse; what's going to happen when it
gets 300 + volts and then the xenon tube extinguishes and "break" comes
for that field? I realize the current is diminishing during the
flash, guess I'll have to try it to find out - but I think I'll try it
on the spider first<g>.
Take care, Malcolm
That is incorrect. The spark coil is typically about a 50 or 100 to 1
transformer. When used in an old automobile, the points close, and a
current builds up in the leakage inductance of the coil. This typically
generates some voltage on the secondary, but not enough to cause a
spark. Then when the points open the field collapses with a time constant
set by the leakage inductance, and the small capacitor that is across the
points. The result is that there is a voltage spike on the primary of the
coil or about 1,000 volts, which show up at the secondary as a 50,000 to
100,000 volts.
If you ever put a CD ignition on an old car you would know that they use a
circuit very much like the one for the pulser, a high voltage controlled
by an scr.
Marshall
At 10:56 AM 10/26/03 -0500, you wrote:
BTW, anyone who has made a home made pulsar can easily make it to be a
shocker as well. Instead of connecting the magnetic coil wound on a VHS
spool to the unit, connect the primary of an old automobile spark coil
to it. Easy, and convenient.
Marshall
[email protected] wrote:
I have been told that you cannot use new automobiles to shock for
venom. It will kill you. Maybe older vehicles were OK. We have used
the spark plug wire from a 2 cylinder motor. We hold a metal rod (with
heavy welder's gloves) stuck into the spark plug cover. We stand on a
few layers of corrugated boxes flattened out to keep from being
grounded? With the motor running (a welder) I hold the rod, and my
husband gets just close enough to the rod to have it arc, or have a
little electrical bolt strike his skin. We shocked each bite, or
eruption, about 10 or 15 times around them and also in the middle of
them. The man who showed us how to do this used a 2 cylinder
motorcycle to shock his wife's bite with great success. My husband has
waited 2 weeks to shock his. His original bite had already cleared
up. I used CS on it, but he had several eruptions after that. We have
been told that he should have stayed down, and not been as active as he
was (he played basketball several times). Have been told that it
caused the poison to circulate to other sites. He is seeing a
Chiropractor who is using acupuncture, Metal cleanse, and UV
light. She cautioned against too much CS ingestion saying it can
accumulate in body if not cleansed. I was having my husband drink
about 8-16 oz a day before we started to see her. She sent him to a
Dr. to get some antibiotics. The Dr. gave him a shot of Rocephin and a
prescription for Keflex. He said the eruptions looked like Staph.
The eruptions seem to slowly be getting better. He has been seeing
the Chiropractor for 5 days, twice a day. We have shocked the
eruptions twice. We haven't told the chiropractor, though. He hasn't
had any new eruptions in 5 days. Still treating 3. They are still
painful. Thanks for the responses. I gave my chiropractor the article
on using nitro patches. She hasn't commented, yet. The guy who
showed us how to use the shock told me that I should have used my CS
generator to shock it as soon as the first bite started erupting. He
said to wet the area and shock it all the way around it. I will
probably try that if I get stung or bitten. I have a homemade CS
generator made with a 19v adapter.
BECKY
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