RE: Early versions of Tesla's coil

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

Original poster: "John H. Couture by way of Terry Fritz <teslalist-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>


RMC -

That induction coil diagram has been confusing Tesla coilers for many years.
If you note carefully the buzzer contact is normally closed at the start and
short circuits both the TC coil and the capacitor when it is closed. The
capacitor can not be charged under these conditions. The coil, however is
being charged with electrical energy.

When the coil is fully charged the contact opens and the current flows from
the charged coil and thru the capacitor and the so called TC primary coil.
The capacitor does not act as a electrical storage device but rather as a
buffer to protect the contact from the inductive kick current from the coil.
The diagram does not show a secondary, however, the primary would normally
have a secondary but no caps as in a tuned TC circuit. The current by
flowing thru the capacitor protects the contact from the inductive kick
current.

The inductive coil TC I show in my book operates from a 6 volt battery and
produces a 70 KV voltage a gain of almost 12000. The inductive kick can give
you a big voltage gain. No Tesla coil can match this voltage gain but they
can produce much more power.

The coil shown in the diagram is called an induction coil because the output
voltage is developed in a completely different manner compared to a Tesla
coil. There are many electrical devices that have been incorrectly labeled
Tesla coils including the Tesla coil leak detectors. However, I have never
taken a Leak Detector apart to check and see if it is a true Tesla coil. I
do know they give a severe shock like a charged coil inductive kick and
unlike a TC where the hi voltage, hi frequency currents can travel on the
surface of the skin.

John Couture

-------------------------------


-----Original Message-----
From: Tesla list [mailto:tesla-at-pupman-dot-com]
Sent: Sunday, July 06, 2003 1:12 PM
To: tesla-at-pupman-dot-com
Subject: Re: Early versions of Tesla's coil


Original poster: "RMC by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<RMC-at-richardcraven.plus-dot-com>



John

  > Was the diagram you received the one that is shown on page 75 in the book
  > "My Inventions" by Nikola Tesla and edited by Ben Johnson?

It seems that the diagram I have been sent does apparently come from the
same source that you refer to.  If this is the diagram for the photograph
whose URL I posted earlier, then I argue that the said photograph and the
diagram are both Tesla coils.

  > I believe the coil in your photo is an induction coil because in this
  > circuit the normally closed buzzer contacts short circuits the capacitor.
  > When the relay coil is energized the contacts open
  > and a current flows from the relay coil thru the Tesla primary and thru
the
  > capacitor.

  >With a true Tesla coil the energy is built up in the Tesla primary
capacitor

I understand the point you make about Tesla coils using a capacitor to store
energy which is then switched into the primary of said coil. I suggest that
the diagram we are now discussing does just that - the contacts are arranged
to be change over contacts.

To start, current begins flowing through the "adjustable iron core(d)" coil
and, via the "primary of tesla coil", charges the condenser. This initial
flowing current immediately pulls in the NC contact, disconnecting the LHS
of the capacitor (which connects to the upright "Terminal of condesner"
ontheleft of the diagram).

When the capacitor has largely charged and the current flowing into it has
decreased, the pulled-in contact drops out and in doing so provides a
discharge path for the capacitor.


Cheers

RMC, England