6 Feb
2011
6 Feb
'11
12:08 p.m.
On 2011 Feb 6, at 8:07 AM, Tony Duell wrote:
You're obfuscating. The point of your comment remains a mystery other
than being to find something to comment on. At this point, no, I don't
want an explanation.
On 2011 Feb 5, at 7:27 AM, Tony Duell wrote:
? The centre-tap is there as an outcome of the design, not innate
intent.
The peak voltage from the power-carryingwires to ground is also an
outcome of the design. The
real-world difference between North American 240V and Euro 240V
is=20=
the maximum potential relative to ground:
NA: 120 VRMS, 170V peak
Euro: 240 VRMS, 340V peak
That's one difference. The other difference is that in the States you
have a centre-tap available. My real point is that no device that requires 220V
should care about
the
voltage to ground (within reason). I would certainly consider a 220V
device that could not satand 220V between one of the power-carrying
wires
to ground ans being unsafe.
Yes, good design would say that it shouldn't matter and I can't say
that I've run across a device where it did matter. But I'm not about to
tell someone working on a device I'm not acquainted with that they
never will. Hence my use of the word 'unlikely' in the earlier message.
But as various people have pointed out, many US 220V
appliances do use
110V for something (controller, timer, etc). That's a bigger problem
when
running them in Europe
Actualyl, I have amn instrument (I think it's my Tektronix 575 curve
tracer) whic hahs sepprate wiring arrangements for 115V, 230V with the
centre earthed and 230V with one side earthed. No, the last 2 are not a
safety thing. Appranetly by having certain points of the transformer
primary close ot ground you get slightly less noise in the instrument.