[vcf-midatlantic] OT - 120v to 240v step up recommendations

[John Heritage]

Thanks Dave, Dave,  and everyone - I reality do appreciate the comments and
thoughts.

The computer in question is the Commodore Amiga 500 (Rev 5A / NTSC) and is
definitely working fine with my other (120VAC at 60Hz to DC output) power
supply.   So I'm assuming the only 'risk' item here for 60 hz input would
be the (AC to DC) power supply created by the engineer and not anything on
the computer itself.

In this case I'm planning to run here in the US (= 60 hz AC) so worst case
it would be a '50 hz transformer running at 60hz'.

Does the frequency of the mains carry over to the DC side somehow?   One
other option the guy mentioned was wiring a 12V/5A DC power supply directly
to the DC to DC converter within the new Amiga power supply, bypassing the
AC to DC conversion.  This would have the benefit of being a smaller, more
power efficient (less conversions) and slightly cheaper solution.

Thanks!

On Sun, May 2, 2021 at 4:38 AM <dave.g4ugm at gmail.com> wrote:

> Even if the grid frequency is "not used for anything" it can still matter.
> Some older, larger computers used resonant transformers and these simply
> won't work.
> Going from the UK/EU 50Hz world to the US 60Hz world is not usually a
> problem. In general transformers are slightly more efficient at 60hz.
> Going the other way can be a problem and US transformers can run warm and
> over heat.
>
> Dave
> G4UGM
>
> > -----Original Message-----
> > From: vcf-midatlantic <vcf-midatlantic-bounces at lists.vcfed.org> On
> Behalf
> > Of John Heritage via vcf-midatlantic
> > Sent: 02 May 2021 00:45
> > To: W2HX <w2hx at w2hx.com>
> > Cc: John Heritage <john.heritage at gmail.com>; vcf-midatlantic <vcf-
> > midatlantic at lists.vcfed.org>
> > Subject: Re: [vcf-midatlantic] OT - 120v to 240v step up recommendations
> >
> > Per the guy who designed it (iComp.De - he makes tons of
> > amiga/commodore custom electronics) - the input frequency doesn't matter:
> >
> > does 60 hz / 240V power vs 50 hz / 240V power matter for this power
> supply
> > if I go the transformer route?
> >
> > It shouldn't - it's a simple rectifier design where grid frequency is
> not used for
> > anything.
> >
> > On Wed, Apr 28, 2021 at 8:13 PM W2HX <w2hx at w2hx.com> wrote:
> >
> > > Are you sure the PS in the amiga is expecting 60 Hertz power? It might
> > > be expecting 50 Hz depending on where it is from. This is a bigger
> > > problem that a transformer won't solve
> > >
> > > -----Original Message-----
> > > From: vcf-midatlantic <vcf-midatlantic-bounces at lists.vcfed.org> On
> > > Behalf Of John Heritage via vcf-midatlantic
> > > Sent: Wednesday, April 28, 2021 4:57 PM
> > > To: Ethan O'Toole <telmnstr at 757.org>
> > > Cc: John Heritage <john.heritage at gmail.com>; John Heritage via
> > > vcf-midatlantic <vcf-midatlantic at lists.vcfed.org>
> > > Subject: Re: [vcf-midatlantic] OT - 120v to 240v step up
> > > recommendations
> > >
> > > Yep - that's exactly what i'm looking for advice on -- I think
> > > transformers are pretty standard/minimalist, but just looking for some
> > > links or models of 'ready to use' step up transformers that will plug
> > > into my US 120V outlet and give me a 240V UK or EU style plug output..
> > >
> > > thanks!
> > >
> > > On Wed, Apr 28, 2021 at 4:49 PM Ethan O'Toole <telmnstr at 757.org>
> wrote:
> > >
> > > > > Hey folks
> > > > > I have a new Amiga PSU coming on from icomp that is 240V only.
> > > > > I'm
> > > > looking
> > > > > for recommendations for a 120 to 240V step up transformer rated
> > > > > for at least 100W (so it doesnt have to work hard).  Preferably
> silent.
> > > Etc.
> > > > > Also what should I avoid in this space ?
> > > >
> > > > I mean you can get a transformer that will take 110 and put out 220
> > > > before the Amiga PSU.
> > > >
> > > > The Amiga runs on voltages that you could find on any ATX power
> supply.
> > > > You could make a cable that would go from the funky square DIN to a
> > > > PC motherboard ATX connector and use any old ATX Flex PSU.
> > > >
> > > >                         - Ethan
> > > >
> > > >
> > >
>
>