Re: Model-T Ford coil

At 12:25 PM 11/25/96 -0700, you wrote:
>>From tesla-at-america-dot-comMon Nov 25 10:59:24 1996
>Date: Mon, 25 Nov 96 07:19 EST
>From: Bob Schumann <tesla-at-america-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Model-T Ford coil
>        I recently got an old Model-T Ford coil. After
>an hour, I finally understood how it works. Pretty
>embarrising to take so long to figure out something so
>old and simple. Anyway, I have only a couple of plans
>for its use in a mini Tesla Coil, wrapping a coil around
>a wine bottle, and wondered if anybody had used the Ford
>coil in a project and what they have done.
>Bob Schumann
Ford coils are simply induction coils.  As I recall, the old Model T used
four of them (one for each cylinder) mounted in a box beneath the dash.
They are still being manufactured for sale to antique car buffs, but are
pricey at about $50 a pop.  They were a standby for the electrical
experimenters of the Gernsback era.  Their innards consist of a primary
wound with (I think), #22 DCC magnet wire on an iron wire core, surrounded
by a secondary of #40 enamelled wire.  There is a tinfoil capacitor across
the secondary to give a "hot" spark. Connections are brought out to three
terminals, one being common to both primary and secondary.  With a clean and
well-adjusted interrupter it will give a 0.75" spark (and kick like a mule
if you get across the terminals).  It was claimed that a Ford coil driven
Tesla coil would give a 4" spark, but none of the coils I built back then
ever did much better than 1"-1.5".