Re: help with a different type of coil

From: 	Rodney Davies[SMTP:rgd872-at-anu.edu.au]
Sent: 	Wednesday, July 02, 1997 9:48 AM
To: 	Tesla List
Cc: 	wawa-at-spectra-dot-net
Subject: 	Re: help with a different type of coil

Hi Kevin,

On Tue, 1 Jul 1997, Tesla List wrote:

> Right now, I'm trying to build a tesla coil, the thing is, it isn't like
> any of the ones (as far as I can tell) that are discussed about in this
> group or are frequently seen on the web.  We used one in my Physics
> class and my teacher said it was a tesla coil, but I didn't recognize it
> as one.  Well, it is rather old, but I will describe it.  It has an
> electromagnetic switch, that once it opens, it breaks its own circuit
> (the power to the magnet) and thus closes again and this cycle repeats
> very fast.  The switch also breaks the current of a separate circuit
> consisting of a power supply, a coil, and a spark gap.  My teacher said
> that breaking the circuit in the coil generates high voldages and the
> sparks to jump the gap.  The coil he used was powered by a low
> voltage/current dc power supply.  The coil is iron core, my teacher said
> it is better for inductance.  I'm not to clear on the inductance stuff.

What you've described is an induction coil - another Tesla invention!

It works similar to a tesla coil, but on DC. (yes, DC TC's do exist too!),
but you should be able to slide the outer-coil off.
The spark gap you described, is the discharge from end-to-end of the
secondary coil...looks like a half-wave TC.

Tesla coils *do not* have iron cores, so it _must_ be an induction coil as
I know some do.

You had better let your teacher know what it really is...otherwise, he's
got the wrong idea about TC's all together...

hope this helps! :-)