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Re: [Amps] HV Switch Mode Power Supplies

To: amps@contesting.com
Subject: Re: [Amps] HV Switch Mode Power Supplies
From: "Will Matney" <craxd@engineer.com>
Date: Fri, 24 Jun 2005 19:42:55 -0500
List-post: <mailto:amps@contesting.com>
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.

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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