Rich,
See below;
>
>
> On Jun 24, 2005, at 5:42 PM, Will Matney wrote:
>
> > David, I was going for 1000 V, and was thinking 1 kV so must have
> > added it and didn't catch it. The graph on the website showed a
> > 1000 V drop over the range of 0-1 ampere. About every power
> > supply I've built using a transformer, with capacitor input, you
> > can divide the no-load voltage by 1.12 or 1.13 (12-13%) and
> > generally find the full load drop in voltage. That switching
> > supply dropped by a third or about 30-35% if I recall after
> > looking at it yesterday +/- 100 volts give or take. Take say 3500
> > Vdc using a standard HV transformer and a regulation of 13%, it
> > would be 3097 Vdc where you can see it's about 303 volts. This
> > 1000 volt drop would cause the plate resistance to swing all over
> > the place I would think.
>
> Correct, but most of the switcher supplies that I've seen have a
> feedback loop that maintains output V with changes in load-I.
Yes, they should have, the same as any voltage regulator. I took a look at the
graph the builder had posted on their website and quoted the figures from what
I seen (1000 Vdc drop over 1 ampere). I looked to see if there was any
schematics for this but the manual which was downloadable didn't have any
prints. I guess you have to buy one to get the manual and prints.
My thoughts were with that big of a voltage swing was whether the tank would
tune in an amp. The graph didn't say how the test was done, CW or SSB. The
swing would be the worst using SSB. Even on AM, that swing would be pretty big
too I would think.
> >
> > Best,
> >
> > Will
> >
> >
> >
> >>
> >> Will Matney wrote:
> >>> David,
> >>>
> >>> You are correct on the regulation. A regular transformer type
> >>> power supply when designed right will have a regulation
> >>> somewherre around 11-14%. In the case of the switching supply, it
> >>> looks like 30-35%. 1000 kV drop over 1 amp is a good bit of sag.
> >>>
> >>> Best,
> >>>
> >>> Will
> >>
> >> I would have thought that cause serious non-linearity problems on SSB.
> >>
> >>
> >> Having gone to a switch mode design, I would have thought they used some
> >> feedback to keep the voltage constant. But it seems not. Given the line
> >> voltage will probably sag too at 2.5kV, you can rekon on over a kV drop
> >> in practice.
> >>
> >> I assume you mean 1kV sag, or 1000V, and not 1000kV !! Reminds me of a
> >> lecturer I know who got fed up with the cleaners moving his equipment
> >> that worked from 12V. So he decided to put a sign on it
> >>
> >> "Danger, 1200000 uV"
> >>
> >> Apparently nobody touched it any more.
> >>
> >>>
> >>> ----- Original Message -----
> >>> From: "David Kirkby" <david.kirkby@onetel.net>
> >>> To: "amps@contesting.com" <amps@contesting.com>
> >>> Subject: Re: [Amps] HV Switch Mode Power Supplies
> >>> Date: Fri, 24 Jun 2005 00:39:13 +0100
> >>>
> >>>
> >>>> Steve Thompson wrote:
> >>>>
> >>>>> Winfried Kriegl wrote:
> >>>>>
> >>>>>
> >>>>>> http://www.wattsunlimited.com
> >>>>>> have a 2500W SMPS. Works fine.
> >>>>>
> >>>>> Looks very nice.
> >>>>
> >>>> But look at the regulation (or lack of).
> >>>>
> >>>> http://wattsunlimited.com/_wsn/page3.html
> >>>>
> >>>>
> >>>> --
> >>>> David Kirkby,
> >>>> G8WRB
> >>>>
> >>>> Please check out http://www.g8wrb.org/
> >>>> of if you live in Essex http://www.southminster-branch-line.org.uk/
> >>>>
> >>>>
> >>>> _______________________________________________
> >>>> Amps mailing list
> >>>> Amps@contesting.com
> >>>> http://lists.contesting.com/mailman/listinfo/amps
> >>>
> >>>
> >>>
> >>
> >>
> >> --
> >> David Kirkby,
> >> G8WRB
> >>
> >> Please check out http://www.g8wrb.org/
> >> of if you live in Essex http://www.southminster-branch-line.org.uk/
> >>
> >>
> >> _______________________________________________
> >> Amps mailing list
> >> Amps@contesting.com
> >> http://lists.contesting.com/mailman/listinfo/amps
> >
> >
> > -- ___________________________________________________________
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> >
> >
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
Best,
Will
--
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