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Re: Flybacks (was To Kevin)
From: John H. Couture[SMTP:couturejh-at-worldnet.att-dot-net]
Sent: Thursday, September 18, 1997 12:04 AM
To: Tesla List
Subject: Re: Flybacks (was To Kevin)
To All -
You would know that the flyback transformer was not a Tesla coil if you
knew how a Tesla coil works. The flyback transformer works by an inductive
"kick" according to the equation V = L di/dt . It is basically an
induction coil. It produces a high voltage at low amperage and is good only
for circuits that require low power. It works by OPENING the inductive
circuit. The output is only a PULSE that is not capable of producing much power
The Tesla coil is a dual RCL tuned circuit. It produces an ultra high
voltage at large currents and is good for ultra high power outputs. It is an
air core resonant power transformer. It uses a dampened sine wave and
produces a high voltage when the circuit is CLOSED. SINE WAVES will produce
larger outputs compared to the PULSES of flybacks. There is a lot more about
Tesla coils that make them unique and capable of doing the job that Tesla
needed for his world electrical system. Up until the 1930's only a TC could
produce the high voltage outputs required for a million volt XRay machine.
John Couture
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At 05:16 AM 9/17/97 +0000, you wrote:
>
>From: Robert Michaels[SMTP:robert.michaels-at-online.sme-dot-org]
>Sent: Tuesday, September 16, 1997 2:38 PM
>To: tesla-at-pupman-dot-com
>Subject: Flybacks (was To Kevin)
>
> The erudition and logic in your post is hard to refute,
> Malcolm on any technical basis.
>
> Howsoforeverbethatasitmay -- I respectfully submit that
> flyback transformers resemble Tesla coils in that flybacks
> generate (and in the practical realization =depend upon=)
> high-voltage at high-frequency.
>
> It is this combination: high-voltage and high-frequency,
> together, that characterizes much of the work and related
> discoveries of Dr. Tesla.
>
> Ergo -- In my book a flyback transformer is a modern applica-
> tion of Dr. Tesla's work. That it also resembles a switching
> power supply does not detract from this. That it does not
> depend upon a tuned primary/secondary serves to differentiate
> it from a Tesla coil per se -- yes that is so. But hey --
> there is precious, precious little everyday use of Tesla
> currents. Don't try to take flybacks away from us!
>
> Fighting for Dr. Tesla, in
> -- Detroit, USA
>
> Robert Michaels
>
>
>
>TL>From: Malcolm Watts[SMTP:MALCOLM-at-directorate.wnp.ac.nz]
>TL>Sent: Monday, September 15, 1997 8:03 PM
>
>TL>Hi Alfred,
>TL> A comment on your comment on my comment :)
>
>TL>> From: Alfred A. Skrocki[SMTP:alfred.skrocki-at-cybernetworking-dot-com]
>TL>> Sent: Sunday, September 14, 1997 1:28 PM
>TL>> To: Tesla List
>TL>> Subject: Re: To Kevin
>TL>>
>TL>> On Sunday, September 14, 1997 5:14 PM Malcolm Watts
>TL>> [SMTP:MALCOLM-at-directorate.wnp.ac.nz] wrote;
>TL>>
>TL>> > My opinion for what it's worth:
>TL><megasnip>
>
>TL>> > I think the flyback is fundamentally an induction coil. It works by
>TL>> > storing energy in the core, then releasing it from core to the load.
>TL>> > The TC we know and love on the other had is a cap discharge device
>TL>> > and is tuned to boot.
>TL>>
>TL>> I fundamentaly agree with Malcolm, a flyback transformer CAN NOT
>TL>> function without its ferrite core, by contrast a ferrite core would
>TL>> destroy a Tesla coils operation. I do differ with Malcom though on
>TL>> the issue of "tuned", typicaly flyback transformers are also tuned,
>TL>> in fact they are designed to resonate at about twice the horizontal
>TL>> oscillator's frequency roughly 30 KHz.
>
>TL>Flyback is a SMPS topology. It is not a requirement of a flyback
>TL>supply that any part of it be tuned. You are talking about one
>TL>designed for a particular application. The one I am building for
>TL>powering my coils is untuned but still a flyback nonetheless.
>TL>Moreover, a core is not a requirement for flyback operation. The only
>TL>thing that differentiates a flyback power supply from a forward one
>TL>is the use of a steering diode on the output side so that the switch
>TL>doesn't directly feel the load. In doing this, turns ratio doesn't
>TL>count in having a say in final output voltage. The only thing
>TL>governing output voltage in a flyback topology is the energy stored in
>TL>the coupled pri-sec inductors and the load on either or both coils if
>TL>coupling is tight. You can achieve pretty respectable coupling k > 0.9
>TL>in an air-cored transformer. You can do better by confining the flux
>TL>to an airgap with a core.
>
>TL>IMHO,
>TL>Malcolm
>
>
>
>