🚀 go-pugleaf

In article <1992Aug30.183748.1399@athena.cs.uga.edu>, mcovingt@athena.cs.uga.edu (Michael A. Covington) writes:
|> There's one BIG possible problem:  The grounding is done differently.
|> 
|> As I understand it, European 220V service is like American 120V service,
|> in that one side of the line is at ground potential.  Right?
|> 
|> American 220V service is different.  Neither side of the line is grounded.
|> What you have is a 240-volt center-tapped transformer with the center
|> tap grounded.  120-volt service uses half of the transformer, with the
|> center tap as "neutral."  240-volt service uses both sides of the transformer.
|> 
|> It's overwhelmingly probable that the power supplies in your equipment
|> will expect "neutral" to be grounded, and will fry something if it isn't.
|> 
|> The best way to deal with the Amstrad PC is to replace its power supply with
|> an American one, or look inside for a 120v-vs-220v jumper or switch (many
|> computers have them).  Ditto the low-powered audio equipment.  The huge
|> audio power amplifier will be more difficult; can you replace its
|> power transformer with one that has a 120v primary?

I would be interested to see *any* power supply which needed
one side grounded ...

Since all of the equipment described (PC excepted) has transformers,
there is no problem.

In electronic workshops (TV repair and the like), the supply is frequently
(read that as REQUIRED TO BE - in the UK anyway) fed via
an isolating transformer - the whole point of which is to remove
the ground reference - both wires "float" w.r.t. ground - then when
you put your finger one one of them, there is no return path, so
you are less liable to be zapped.

Unless anyonme can give a good theoretical reason why any design
of power supply should require grounding (and I would argue that any
supply so designed is bad design), I would have no hesitation
is saying "plug it in".

If you are really paranoid, use a 110 -> 220 transformer, or a
220 -> 220 transformer, and ground one side of the secondary
(If you go this far, you probably also beleive in fairies ...).

Philip