Re: Simplest TC of all?

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

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
> 
> Original poster: "robert heidlebaugh by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <rheidlebaugh-at-desertgate-dot-com>
> 
> Joyon: Yes it is possible to design a tuned auto transformer Tesla coil. Is
> it easy??? No. Is it safe ??? No. The primary problem with this design is
> the fact that total primary power is part of the output so any current path
> is combined power, not just secondary power. The second main problen is wire
> size. Any over current discharge can burn out the total coil. Most TC coils
> use copper strap, tubing, or heavy wire to tolerate the current surge. The
> secondary is fine wire. Since the primary current and secondary current are
> isolated the secondary dosent flash like a flash bulb in a cloud of smoke.

It's certainly safer to have two separated coils, but an autotransformer
coil (Oudin coil) is perfectly safe if properly grounded. Look at the
schematic:

              (=====) Terminal
                 |
                 L2
                 |
   o------+--C1--+
          o      |
  PSU    gap     L1
          o      | 
   o------+------+--o Ground

C1 and L1 form a filter that effectively blocks any low-frequency
energy coming from the power supply. Even if the connection between
L1 and ground is lost, there is still C1 and the large inductance
of L2 to block any high current that would try to pass to the
terminal.

Antonio Carlos M. de Queiroz