Re: Small simple coil (beginner)

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-uswest-dot-net>" <jimlux-at-earthlink-dot-net>

info on ignition coil properties:
http://home.earthlink-dot-net/~jimlux/hv/igncoil.htm

If you use a transistor to drive the coil, bear in mind that the voltage
across the transistor will spike up to around 400V when you turn it off.
Try to find a transistor designed for ignition amplifier duty, or, even
better, cannibalize an ignition amplifier at the auto junk yard.... They are
designed to limit the current, generate the right waveforms, etc all from a
very low power input (inductive or optical pickup).  My 25 year old 280Z has
an amplifier that would work just fine, and I imagine that Nissan used that
part on many different models for many years, and they should be virtually
free at a "pick your part" kind of place.

HEI ignitions also have a nifty amplifier (that's what that Motorola chip is
designed for), but I don't have any model numbers or hookup info.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, May 02, 2001 7:02 AM
Subject: Re: Small simple coil (beginner)


> Original poster: "Malcolm Watts by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>
>
> On 1 May 01, at 19:24, Tesla list wrote:
>
> > Original poster: "Jake Draper by way of Terry Fritz
> > <twftesla-at-uswest-dot-net>" <cybermecium2-at-home-dot-com>
> >
> > I have had bad luck in the past with ignition coils and I was
> > wondering just how exactly you could make an ignition coil powered TC
> > that would give me a 6 inch spark. I want to know about what kind of
> > driver, primary, secondary, capacitor, spark gap, etc. I really need
> > the help, thanks.
>
> 150mJ or so of TC primary cap energy should be more than enough to do
> it with a reasonable TC on a single shot basis. To know how much
> voltage to apply to the ign coil primary to get you there you need to
> know the inductance of the coil (for energy calculation) and its DC
> resistance (to know what voltage to apply to get to the target
> current). Ign coil primary energy = 0.5LI^2  where L is inductance of
> its primary and I is the peak primary current.
>       Don't ask me for specifics on my old coil. I got rid of it long
> ago. It was built about 20 years ago.
>
> Malcolm
>
> >
> > ----- Original Message -----
> > From: "Tesla list" <tesla-at-pupman-dot-com>
> > To: <tesla-at-pupman-dot-com>
> > Sent: Tuesday, May 01, 2001 5:02 PM
> > Subject: Re: Small simple coil (beginner)
> >
> >
> > > Original poster: "Malcolm Watts by way of Terry Fritz
> > <twftesla-at-uswest-dot-net>" <m.j.watts-at-massey.ac.nz>
> > >
> > > Hi Matt,
> > >         I couldn't help chuckling on reading your post (no offence
> > > intended!).
> > >
> > > On 1 May 01, at 16:20, Tesla list wrote:
> > >
> > > > Original poster: "The Swami by way of Terry Fritz
> > > > <twftesla-at-uswest-dot-net>" <devsibwarra-at-hotmail-dot-com>
> > > >
> > > > Hello
> > > > I am a student in Sarnia Ontario,
> > > > Im looking for a schematic for a simple coil that I can build and
> > > > experiment with.
> > > >
> > > > I have grade 12 advance physics knowlege,
> > > >
> > > > Im looking to biuld one that wont arc more than an inch becuase I
> > > > really dont know how to control the thing, but I am very
> > > > interested in learning more.
> > > >
> > > > PLease reply to my personal e-mail or send a copy to my e-mail so
> > > > the list can benefit too.
> > > >
> > > > Thanks
> > > > -Matt
> > >
> > > An inch of spark is what most people who've built a coil and have no
> > > idea how to tune it usually get. So basically you could accomplish
> > > your goal by winding any old secondary, any old primary and use a
> > > spark plug for a gap. I do think you should aim for a loftier goal.
> > > a 6" spark is possible from a TC powered from an ignition coil.
> > >
> > > Malcolm
>
>
>
>
>