Malcolm Stebbins wrote: > 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. >
Who said anything about a transistorized system? I was talking about an old spark coil, from something like a 1960's car. > > 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. OK, that is exactly what I was saying. That when the points open there is a rapid collapse in the field that generates a voltage of serveral hundred volts, and that is what gets coupled to the secondary for the spark. > 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, Once again exactly what I said. > 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. So the transistor ignition works the same way as the stand one, so I am even correct for it as well. > > 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. OK, so I am a little high on the output voltage. That was not what the message was about, it was givin the information that you just gave above, that the turns ratio is only about 100:1, and that the spark is generated when the points break, not when they make. > > The systems described did not rely on "leakage inductance"; OK, I just checked definitions, and I guess what I meant was primary inductace. They sure called it leakage inductance when I was at the University. http://www.geofex.com/Article_Folders/xformer_des/xformer.htm > 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. OK, primary inductance. Marshall > > 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 >> >> >> >> --- >> >> Incoming mail is certified Virus Free. >> >> Checked by AVG anti-virus system (http://www.grisoft.com). >> >> Version: 6.0.516 / Virus Database: 313 - Release Date: 9/1/03 >> > >> > >> > --- >> > Outgoing mail is certified Virus Free. >> > Checked by AVG anti-virus system >> > (http://www.grisoft.com). >> > Version: 6.0.516 / Virus Database: 313 - Release Date: >> > 9/1/03 >> > >> >> --- >> Incoming mail is certified Virus Free. >> Checked by AVG anti-virus system (http://www.grisoft.com). >> Version: 6.0.530 / Virus Database: 325 - Release Date: 10/22/03 > > ---------------------------------------------------------------- > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.530 / Virus Database: 325 - Release Date: 10/22/03 >
