System/34 contd.

From: Philip.Belben_at_powertech.co.uk <(Philip.Belben_at_powertech.co.uk)>
Date: Wed Feb 18 11:44:21 1998

> For one thing, what is the CE Panel? The thing is in a corner, with
> the end that has the floppy drive on it visible, as well as the side

Someone else has already given a far better reply than I could.

> that has a small power switch on it. I went down to Radio Shack, they
> only had 220-110 transformers that could handle up to 40 Watts. I have
> a hint this might not be enoug ;) Also, they had 110-220 transformers.
> Could I just wire one of those backwards and get the same result?

Possible but not a good performer. Step-down transformers are usually
wound for around 220-120V and allow for 10V or so of voltage drop.
You'd be lucky to get more than 200V out on any sort of load.

Also, 40VA is about 100 times too small :-( Try industrial equipment
suppliers - 1kVA, 3kVA, even 5kVA transformers should be obtainable.
And the bigger it is the less it'll suffer from voltage drop.

> Wouldn't it be easier to just wire two 110 volt plugs together like
> I was told I could try if I like "but I would far better notter"?
> IS this indeed like trying to move heat from a cold to a hot object?

Yes, insofar as it can be done, but don't just connect it up and expect
it to happen. And if you get it wrong you'll probably melt the cold
object, um, I mean wiring, not to mention causing a big flash and bang
and/or your death. The two sockets to which you'd have to connect are
almost certain not to be in the same room. If you really want to go
down this route, here are some things to think about:

First, use 3 pin plugs wherever possible - reversing the polarity of a
2 pin plug at any point during the following procedure could quite
literally be fatal.

One pin of every 110V socket in the house is a "neutral" pin - at
ground potential but not part of the ground connection. The other pin
of each socket is "live" at 110V to ground.

In each socket, identify the neutral pin if you can (a voltmeter
between power pin and ground _should_ do it - if you get 0V or
something silly like 40V on each side, you haven't found ground)

To evaluate a pair of sockets connect the voltmeter between the live
pin of one and the live pin of the other. You should get either 0V or
220V (+/- about 20V in each case). If you get 220V you _may_ be onto a
winner.

The final barrier is protection. Earth leakage protection (GFCI I
think it's called in the US) is almost universal. If the two circuits
are on the same GFCI relay, you're OK. If they are not, you're not.
The test is, connect an ordinary table lamp (or similar) between live
on one socket and neutral on the other. (Check with voltmeter first -
it should give 110V.) If the GFCI trips, you can't get 220V by this
method.

If the GFCI remains stable, you wire up a junction box that takes live
from each socket plus ground from somewhere safe and feeds a 220V
socket.

Now, are you still thinking of using that method? If so, you shouldn't
be!

Seriously, I'd recommend extracting the PSU from the machine and opening
it up. You never know, it may be easily modifiable to 110V operation.
Alternatively, you may be able to substitute one or more 110V PSUs to
power the LV outputs in the same manner.

Finally, if the machine hasn't been powered up for a few years, you
should definitely remove the PSU, power it up with no more than light
bulbs on the outputs, and measure voltages.

Philip.
Received on Wed Feb 18 1998 - 11:44:21 GMT