The other requirement that I know of is to make sure all downstream supplies
have a floating DC chassis ground. This can be confirmed by checking
continuity between the DC output and case. The leading supply SHOULD have
the DC ground bonded to the chassis. All of the supply chassis should
then be bonded together and fed from a common AC input source. So in the
end every supply should have a chassis at the same ground potential as the
other station equipment while the DC output of the other supplies are
floating above potential (which is what we want in order to increase
voltage).
The other thing to consider is how the regulation my be compromised.
Correct me if I'm wrong, but I imagine that if each supply is regulated to
+/- 5%, then this margin should increase with every supply in the chain. So
four 12V supplies may only be regulated to +/- 20%, or vary by almost 10V.
I should say that I have never personally used power supplies in
series but that is how it should work in theory.
Anthony
On Thu, Apr 10, 2008 at 2:21 AM, <d.cutter@ntlworld.com> wrote:
> I've often wondered about series connecting switchers. Can the experts
> tell us if there are any odd start-up conditions that might need attention?
>
> I once made a +/- pair of supplies running from the same switcher source
> and found I needed a parallel diode on the output of each to allow start-up.
>
> David
> G3UNA
> >
> > From: "Anthony Rick" <asrick@gmail.com>
> > Date: 2008/04/09 Wed PM 09:21:29 BST
> > To: "Oleg Skydan" <sov1178@rambler.ru>
> > CC: amps@contesting.com
> > Subject: Re: [Amps] Dual power supplies in EB104 4X MRF150 design
> >
> > Thanks for the replies.
> >
> > It appears that the series option may be the best logistically as far as
> I
> > have investigated. I even wonder about pulling the boards from four PC
> > power supplies that can be had for very little and placing them in a
> series
> > configuration. This would provide 12, 24 and 48 VDC ouputs if needed.
> >
> > With so much of these computer/networking supplies available it is worth
> > some ingenuity to find a way to utilize them.
> > Anthony
> >
> > On Wed, Apr 9, 2008 at 11:52 AM, Oleg Skydan <sov1178@rambler.ru> wrote:
> >
> > > Hi, Rick!
> > >
> > > Try to look for the 24V/20A supplies and use two with series
> connection...
> > >
> > > Kind regards,
> > > Oleg
> > > 73 de UR3IQO
> > >
> > > ----- Original Message ----- From: "Anthony Rick" <asrick@gmail.com>
> > > To: <amps@contesting.com>
> > > Sent: Monday, April 07, 2008 7:34 PM
> > > Subject: [Amps] Dual power supplies in EB104 4X MRF150 design
> > >
> > >
> > > Hi all,
> > > >
> > > > I'm working on building a solid state amp based on the EB104 design,
> and
> > > > cheaply. The only constraint that is causing problems is the power
> > > > supply. It appears that a single 50V/20A is going to be pretty
> > > > expensive
> > > > while 48V/10A supplies are readily available as telecom surplus for
> > > > pretty
> > > > cheap. Looking at the EB104 schematic (
> > > > http://www.communication-concepts.com/eb104.htm) it seems probable
> to
> > > > power
> > > > each MOSFET pair from a separate supply with only the need for an
> > > > additional
> > > > isolation capacitor.
> > > >
> > > > Unfortunately the supplies I am seeing, usually Lambda, are not
> designed
> > > > for
> > > > parallel operation so that easy alternative is not an option.
> > > >
> > > > Any thoughts?
> > > >
> > > > Thanks,
> > > >
> > > > Anthony
> > > > NR9R
> > > > _______________________________________________
> > > > Amps mailing list
> > > > Amps@contesting.com
> > > > http://lists.contesting.com/mailman/listinfo/amps
> > > >
> > >
> > >
> > _______________________________________________
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> > http://lists.contesting.com/mailman/listinfo/amps
> >
>
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