Re: Car Coil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "R Heidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

on 10/26/01 8:01 AM, Tesla list at tesla-at-pupman-dot-com wrote:

> Original poster: "Matt Skidmore by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <fox-at-woozle-dot-org>
> 
> I know its been covered before, but i thought i'd hit upon something new
> for building an automobile powered coil. And its 3 am and i cant stop
> thinking about it.
> 
> But, i was having a lengthy conversation with one of the electronics
> professors at my college about my tesla coil hobby. I brought up a
> question about how one might run these beasts using a dc source. sure
> there are oscilators and tubes if you can think about ways to get them to
> work but he showed me a rather simple idea. he suggested using a dc motor
> to create the signal needed to drive a standard ac transformer. of course
> this would be more of a pulsed dc signal.
> 
> intreaged, i carried a 12kv 60 ma neon transformer down to the lab for
> futher experimentaion. i hooked it up to a signal generator to the low
> voltage side and put a volt meter across the HV end and started fooling
> with the generator. i set the generator to square wave to simulate pulsed
> dc. it outputting 15v rms (not peak to peak) measured with a volt meter. i
> found that i got the highest results with square wave at 700 hertz. to
> futher simulate the pulsed dc i put a diode on one of the terminals going
> into the LV side. it cut my HV voltage down to 215v. still not bad.
> 
> ok so you may be thinking so what? well if you can get some high current
> drawing motor such as a starter motor and use it to create the pulsed dc
> to drive a transformer then you might be able to make a car coil. the
> transformer could be something like an ignition coil, or 1 or 2
> transformers to crank up the voltage.
> 
> i know theres problems. but theres also benefits here too. first off, the
> motor is going to run at an unknown frequency. but hopefully better than
> 60 hertz and not so fast that it will pass up the maximum "sweet spot" on
> the transformers (which was 700 hertz for mine). also, since the motor is
> creating the frequency then it would be also useful for being a perfectly
> phased spark gap. i drew up an illistration you get hit up:
> http://foxxz-dot-net/tesla/carcoil.gif
> 
> grounding. if you're going to try and run this off your car, then you can
> try and go ungrounded or you can try this other trick. i was talking to
> the aviation fuel truck driver at an aitport where my father works. there,
> they have to keep everything perfectly grounded while fueling up as not to
> set the place ablaze. before the trcks started using special tires, they
> drug a short length of chain under the truck to help discharge. this might
> work somewhat well if youre attempting to ground a moving object.
> 
> of course i realize all the dangers of running such things near flamable
> liquids and that it could potentially fry electrical systems of the
> vehicle. but on another thought, one could also install a second
> alternator to run their coils from too.
> 
> dont take me too seriously :D
> -matt
> 
> 
> 
KEEP ONE SMALL THOUGHT the capacitor used on a car coil (.23uf) is chosen to
make the primary winding resonant with the secondary winding for maximun
voltage out. this will get you about 36kv out to drive your coil.If you use
the circuit common to cd ignitions on racing cars you should get about 3
times the voltage out. Dont try to push the coil any more than that or the
insulation of the coil will break down.
    Robert H