[AMPS] Transformer ++

[jeff millar]

Jeesh...

Try to make some helpful suggestions and discuss
something more advanced than transformers and
we get a condescending attitude.

Why, exactly, would a switcher have a slow
startup time?  The one I designed (using a
commercial control chip)  started switching within
a microsecond of the input voltage rising
above it's turn on point and had managed to
pump up the output inductor to full voltage and
current in a few cycles at its 1 MHz switching
frequency.

Consider a class D audio amplifier...think of it as
a switching power supply with a loop bandwidth
of 20 kHz....no big deal.

If you don't understand switchers or only know
what some manufacturer told you, fine. But, I've
designed them on and off for a long time.

But, we agree on the need to drop the discussion.

jeff, wa1hco

----- Original Message -----
From: Alex Von Yonkers <avy@qwestonline.com>
To: jeff millar <jeff@wa1hco.mv.com>; <amps@contesting.com>
Sent: Sunday, March 25, 2001 12:53 PM
Subject: RE: [AMPS] Transformer ++


>
>
> > -----Original Message-----
> > From: jeff millar [mailto:jeff@wa1hco.mv.com]
> > Sent: Sunday, March 25, 2001 12:13 PM
> > To: avy@qwestonline.com; amps@contesting.com
> > Subject: Re: [AMPS] Transformer ++
> >
> >
> > You missed my point.  My design receiver consisted of a
> > switching power supply _and_ associated digital logic with
> >  wideband A/D running with high dynamic range an a
> >  -110 dBm received signal.  This shielding and filtering
> > requirements include all the switching energy _and_ all the
> > digital logic, a more difficult problem than just power
> > supply alone.
> >
> > By the way, since this monster just runs the PA, it seems
> > that to kill receiver noise, JUST TURN IT OFF...should
> > have thought of that before.
> >
> Jeff... let's leave it here ... you really need to do the research before
> making assertions :)
>
> But to answer this; any PS has a finite turn on time. The switchers are
> quite slow... averaging around 1 Second. This precludes the usage of the
> amplifier
> in CW mode where you will lose the first character because the switcher
did
> not come on in time. Also  Break In and VOX operation will not be
possible.
>
> Just think about it :)
>
> Alex
>
>


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