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Re: tube coils
Tesla List wrote:
>
> > Subject: tube coils
>
> >From hullr-at-whitlock-dot-comFri Sep 6 22:14:47 1996
> Date: Fri, 06 Sep 1996 11:51:51 -0700
> From: Richard Hull <hullr-at-whitlock-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: tube coils
>
> Tesla List wrote:
> >
> > >From major-at-vicksburg-dot-comThu Sep 5 22:18:48 1996
> > Date: Thu, 05 Sep 1996 18:26:27 -0500
> > From: RODERICK MAXWELL <major-at-vicksburg-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: tube coils
> >
> > I have not even finished my first capacitor discharge tesla coil and already I,m
> > looking forward to building a tube driven coil! I've odered a couple of books from
> > I.T.S. __Vacuum Tubes In Wireless Communication__ by Elmer E. Bucher ,and __Vacuum Tube
> > Tesla Coils__by J.F. Corum and K.L. Corum. I have built several high voltage projects
> > using induction coils and a solid state Mosfet driver, but I have never built
> > __anything__ that uses tubes.
> > In __Vacuum Tubes In Wireless Comunication__ it describes the vacuum tube as a
> > rectifier. It also shows the direction of electron flow from the filament to the plate.
> > This part I comprehend and understand well. What I have a hard time visualizing is
> > current flow from the plate to the filament! If the flow fom the filament to the plate
> > is composed of electrons, what is current flow from the plate to the filament composed
> > of and what is the mechanism that allows this to happen? Is it simular to hole flow in
> > semiconductor material???? Could someone that has experience with tube electronics
> > please answer these questions for me so I can sleep nights?
>
> We are all "shabby, shabby bastards" (Monty python - life of bryan)
>
> We have always been at the mercy of teachers. They have done their best
> to illiterate and give us warm and fuzzy feels for the mechanism behind
> electrical and electronic goings on. In doing this they have educated us
> and left some of us with false impressions. The only real world fact is
> that electrons do, indeed, leave the heated cathode and flow to the plate
> in a vacuum tube. I was of the very old school and learned electron flow
> for the sake of vacuum tube education (- flows to +). 1950's. With the
> transistor coming on strong while in college, I had to learn current
> flow to mesh with the quantum goings on in semiconductors (+ flows to
> minus) 1960's. Either one is usable if you keep your wits about you.
>
> I was fortunate to learn both and am not confused by them. There is a
> deeper understand here. There are no holes in real life and the
> semiconductor models we are taugh are conventions and not fact! They
> help us grasp and use the semiconductor in circuits. The understanding
> we receive is an valuable and highly useful illusion.
>
> The important thing to remember in current flow is that in tracing out a
> circuit we always "fall" from a high potential (+) to a lower one (-).
> This leaves all entry points on circuit components, positive and all exit
> points, negative. Electron flow is all but disgarded now and is only
> readily obvious in tubes. This is the only place in electronics where we
> can really be sure of what is really happening on even the most
> microscopic scale!! It was always hard to envision a voltage climbing up
> to a higher potential through a resistor. Even way back then. The
> current flow model is more intuitive. Forget that "nothing" in the
> current flows through the tube in the reverse direction, it is just a
> convention which must be obeyed if you are to use it well. In everything
> electrical, we are really only moving phantom charges about.(except in a
> vacuum tube)
> In copper wires, electrons do flow, but only very very slowly.
>
> Richard Hull, TCBOR
Thank you for answering that most aggravateing question! But it still leaves me with
the feeling that I really don't have the full story. I guess it not possible to really
understand the actions of somthing that you can't grasp in your two hands!