Re: why 4 Ohms in PARALLEL with trigger coil primary?

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>


Terry, Ted, All
The 4 ohm resistor got into the circuit kinda on accident, I was messing
around with the gap hooked to a primary and when i connected the
resistor before the cap i could maintain the trigger arc, by itself,
throughout a wider range of the dimmers adjustment.
I tried several different values but the 4 ohm seemed to work best?
I connected the tank circuit and it seemed that the main gap fired
smoother with, then without?
It could be true that it does little in circuit, I will try to look on a
scope at the difference.
Maybe every auto coil is different, every dimmer is different and needs
it's own setup? But the gap works well enough with just the
dimmer-cap-coil that coilers shouldn't be scared away from using it.
The reason i went to a higher current triac is from the scope traces
from terry showing the spiking that was going on, I figured that with
the basic three component gap, It could use a stronger triac? After i
replaced the wimpy triac with the hefty one, i didn't blow any more
units.
The schematic Ted made and with the resistor in line to the cap, I know
works so it at least is a good starting point.
Maybe as more coilers start using the gap, we will see a bunch of mods
to increase performance?


> Hmmmm.  There is a chance they are just not doing too much.  Or maybe they
> are doing something wonderful...  I am not at all sure.  Maybe Marc knows.
> If it works, it works.  
>         Terry
> 
> >
> >Safety First
> >
> >Ted
> >
> >-----Original Message-----
> >From: Tesla list [mailto:tesla-at-pupman-dot-com]
> >Sent: Wednesday, October 17, 2001 10:13 PM
> >To: tesla-at-pupman-dot-com
> >Subject: RE: why 4 Ohms in PARALLEL with trigger coil primary?
> >
> >
> >Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
> >
> >Hi All,
> >
> >We have been having some (sort of off list) discussion about the 4 ohms of
> >resistance across the HEI coil's primary in Ted's plans...  It seems like
> >these resistors would burn right up.  We are a little unsure of what is
> >going on but I thought you all should know about this mystery too incase
> >you try it.  If "you" figure it out, let "us" know :-))
> >
> >---------------------
> >Hmmmmm,
> >
> >If you but 4 ohms directly across the ac line, it will dissipate 3600
> >watts...  The dimmer would limit that to maybe 1000 watts...  Something
> >strange must be going on there.  However, if it works, it works.  But I
> >think there is a good chance they are blown open which would probably have
> >little effect.  I would leave it for now and maybe when you can play with
> >you coil at length, check into it more.  Next time you see the coil, you
> >may want to double check to see that they really are across the neutral and
> >hot wires out of the dimmer and not in series.  Check the resistance if you
> >can.  I bet it is higher than 4 ohms :-))
> >
> >Cheers,
> >
> >       Terry
> >
> >
> >At 12:40 PM 10/17/2001 -0500, Ted Rosenberg wrote:
> >>Hi Terry. Hey, if I can type at 6AM (I work from 7 to 4  :)....
> >>No matter.
> >>
> >>The resistance was based on Marc's picking different low values on his
> >first
> >>iteration of connections...remember? The 10µF motor run cap and the 10 ohms
> >>etc. It was about the same time you were using the 250W huge reistors? (I
> >>have two...any ideas? They do not make good wind chimes!)
> >>
> >>Then Marc said that 4 ohms would be OK but he was not terribly clear as to
> >>exactly where!!
> >>Well, I didn't have 4 ohms. So two 8's in parallel gave me the 4 <at 40
> >>watts>. Then I put them in series in the line and I almost burned up the
> >>coil from the heat. That's when I got hold of you and you suggested across
> >>the HEI. And that worked.
> >>
> >>Does that clarify? Or should I try and followup with Marc?
> >>
> >>-----Original Message-----
> >>From: Terry Fritz [mailto:twftesla-at-qwest-dot-net]
> >>Sent: Wednesday, October 17, 2001 12:33 PM
> >>To: Ted Rosenberg; 'Scott.L.Hanson-at-seagate-dot-com'
> >>Subject: RE: why 4 Ohms in PARALLEL with trigger coil primary?
> >>
> >>
> >>Hi Ted and Scott,
> >>
> >>I forwarded this to the Tesla list by accident.  Sorry bout that...  You
> >>may want to write me at:
> >>
> >>terrellf-at-qwest-dot-net
> >>
> >>So the sleepy Terry can't just forward all the morning mail on without
> >>checking who it is addressed to...
> >>
> >>I did not understand why the resistors would be in parallel either :o)  I
> >>thought they should be in series.  I figured, well, I guess it works for
> >>Ted ok...  You may want to check them with an ohmmeter.  I wonder if they
> >>blew open in the first second and they are just open now.  If they were
> >>open, you may not notice (maybe they don't matter...).
> >>
> >>Cheers,
> >>
> >>      Terry
> >>
> >>At 07:02 AM 10/17/2001 -0500, Ted Rosenberg wrote:
> >>>Hi Scott and thanks for the compliment.
> >>>I have some answers for you but please understand, as I said in the paper,
> >>I
> >>>was the technician. Marc and Terry Fritz deserve the "why" rewards!
> >>>
> >>>I originally had the 4 ohms in-line. the resistors got SO hot that they
> >>>would have burned the wood etc etc. I desparately e-mailed Terry as Marc
> >>was
> >>>unavailable. After some discussion, Terry suggested the new position
> >>>and...it works. I really can't give you a better reason. Sorry. Perhaps
> >you
> >>>might ask Terry about that. Who knows, I might learn something  :))
> >>>
> >>>I do not own an oscope although I can borrow one.
> >>>I had to get this coil into the Hangman's House of Horrors and I was
> >>running
> >>>out of time. So all seriosu tweaking, checking with scope, adding welders
> >>>glass etc, will have to wait until the coil returns home after Oct 31.
> >>>
> >snip...
> >