Russell McMahon wrote...

>It seems to me that we all seem to be getting a bit too wound up over =
this.

Oh, I don't know about that.  This is rather fun, actually.

>The circuit that I provided is by no means an
>optimal one if you are wanting highest efficiency, cleanest waveforms,
>lowest losses, controlled frequency or even well a defined operating =
point.

Thank you.  That, in a nutshell, was my point.

>It is however a superb solution for some applications.

I'm sure it is, particularly if you've tested it thoroughly and have
been satisfied that it will function properly in your application
under whatever conditions it needs to function.  What works, works.

As to whether or not it is a solution in anything I am likely to be
doing, that is another matter: I seldom need output currents exceeding
a few score of milliamperes, and I never have to deal with input
voltages above a few dozen volts.  Something that pumps out ten volts
at over half an ampere, with an input ranging from 50 volts to 200
volts, is a curiosity, and no more.

But if that's what you need, and this circuit works for you, that's
great.

>Re how nactively this circuit oscillates. - "try it, you'll like it". I
>don't know how it works in SPICE but in practice it starts as cleanly as=
 any
>oscillator I have ever seen - immediate sharp transistion from linear =
mode
>to full clean oscillation.

Oh, it oscillates in SPICE just fine- with gleeful, wholehearted
abandon, I'd say.  :)

It is the limitations in how that oscillation is controlled, and the
consequences for output ripple and regulation, that I find
unsatisfactory.  For me, that is.

G'nite...

Dave

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