Original poster: "Scott Bogard" <teslas-intern@xxxxxxxxxxx> James,I am not an automotive engineer (or even a mechanic) but I have spent many hours in a junkyard, and (I admit) am strangely fascinated by random car parts (even though I usually don't know what they do!). Anyway, I have seen two types of distributors (I'm sure there are more). 1. a near contact rotary (Works like a conventional rotary spark gap, the "condenser" builds a charge, and jolts it through the coils primary, as this happens the points line up and fire from the secondary to the ground, through the spark plug. Some people have tossed around the idea of using one of these for a rsg, but have dismissed it as the system wattage would be incredibly low.) 2. A contact gap (I have only seen these on 1 of 2 cylinder engines, but a cam actually makes contact at the perfect intervals, as the condenser charges, and discharges through the primary, and so HV is sent from the secondary to the spark plug.) My design uses a rotor that spins between two fixed rolling or possibly sliding contacts, I will try building it sometime, as if it works it will have great potential (but in all likely hood, I will be plagued by all sorts of jamming, heating, scorching, warping, and "quenching" problems). As there is no spark, "quenching" is a misnomer (except for residual spark before and after contact, which is minimized but probably not entirely prevented by oil) but I will still have to figure a way to prevent it from dumping too much energy, which it will do incredibly fast, as it is conducting through metal, instead of an arc! Perhaps adding resistance, or a current limiting inductor on either side of the gap, but that may waste some energy, defeating the whole purpose. I could always make the wheel huge, and spin really fast, but once again, this may not be practical. I think inductors may be the way to go. Oh well, I won't have time to try it until school lets out in 3 weeks anyway, so I have plenty of time to ponder! Thanks to all for your input guys, I really appreciate it.
Scott Bogard.P.S. I never thought of using mercury in a gap, but I did think of using salt water. Mercury is (was rather) used to make contact in old thermostats, but my thinking is, if a gap can melt tungsten, it will explode mercury, leaving nothing behind but an almost unquenchable mercury vapor arc (which would look really cool; and if it weren't for the obvious health concerns, I might try it anyway!). A fluid gap would be nice, but getting steady controlled pulse would be a nightmare mechanically, and they might splash, or stick to contacts, which would be bad. But I may try that as well anyway (sometimes I surprise myself, even if something doesn't work, I still learn, and sometimes cool unforeseen side effect make it worth while anyway.)
From: "Tesla list" <tesla@xxxxxxxxxx> To: tesla@xxxxxxxxxx Subject: Re: contact spark gap Date: Sun, 15 Apr 2007 15:38:53 -0600 Original poster: "James Howells" <james@xxxxxxxxxxxxxxxxxxxxxxx>I am not too sure, but is this not how a car ( automobile) distributor cap used to work ?Protected by www.SpamJab.com {UgzndUInruKjv2Cy9r} ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx> To: <tesla@xxxxxxxxxx> Sent: Sunday, April 15, 2007 3:08 AM Subject: RE: contact spark gapOriginal poster: "earl rhodes" <earl_1975@xxxxxxxxxxxxx> hi scott and allok full contact spark gap that sounds like it might work if your dealing with low power but as power increases so does the wear on your very small piece of bridging electrode i dare say it would desintegrate quite quickly or simply overheat and damage or warp the disc plus a solid state device whatever the size would be about a million times smaller ,tesla mentioned a mercry break this also was supposed to be a sparkless gap ive thought and thought about this thing and i dare say others have too the words "holy"and "grail"jump to mind so go for it anything thats even close to working will turn you godlike lolregards earl but then again i have no idea what im talking about!!From: "Tesla list" <tesla@xxxxxxxxxx> To: tesla@xxxxxxxxxx Subject: contact spark gap Date: Fri, 13 Apr 2007 22:49:56 -0600 Original poster: "Scott Bogard" <teslas-intern@xxxxxxxxxxx> Hi everybody.Since everybody is talking about spark gaps, I figured I'd throw out an idea I've had rolling around in my head for a while. A spark gap has losses in the spark, but solid state cannot handle the raw power a spark can (not yet anyway), so what if we eliminate the losses by having direct contact, and eliminate the power issue by dumping the semiconductors? Here is my idea, take a rotary spark gap, and cut the disk mounted electrodes flush with the disk surface, then mount brass bushings between two shafts, pinching the disk between them. As the disk turns it will make contact with the bushings and complete the tank circuit, dumping loads of power into the primary. The obvious problem with this is it will arc before it rolls over the contact defeating the whole purpose, but my thinking is you could use a smaller rod to increase "quenching" and submerge the whole thing in mineral oil to keep stuff cool and cut down on spark, but you will need a really tough motor. Has anybody out there tried this already? would there be any benefit? would it be as difficult to build as I think it would be? Just curious, thank you much.Scott Bogard. _________________________________________________________________MSN is giving away a trip to Vegas to see Elton John. Enter to win today. http://msnconcertcontest.com?icid-nceltontagline_________________________________________________________________ MSN Hotmail is evolving - check out the new Windows Live Mail. http://ideas.live.co.uk/
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