You don't have the schematics for this anywhere? The PSU is separate
and it looks like I could plug in a PC power supply if I knew pinout.
As for useful things, I would also suggest an older model printer,
a 5.25" drive, and, if possible, an 8" drive. Then, I would say a
VOM is obligatory either way.
>
>This is rapidly becoming a FAQ here - how to convert between 110V and
>220V mains.
>
>By far the easiest and safest way is to use a step-up transformer. It
>doesn't need to be an isolating transformer - an autotransformer is
fine.
>You feed 110V in and get 220V out. Since 240V -> 110V transformers are
>fairly common in the UK, I would guess you can get the reverse in the
States.
>
>If you can't find a suitable transformer, then there's a sort-of kludge
>that works, but you need to take a little care when wiring it up.
>
>Get a mains transformer with _2_ 115V (or thereabouts) primary
windings.
>Such transformers are fairly common, since by connecting the primaries
in
>parallel you can use them in the States, and by connecting them is
series
>(230V) you can use them in Europe. It doesn't matter what the
secondaries
>are, as you're not going to use them.
>
>Connect the windings in series, like you would for 230V mains. Connect
>the output across the 2 windings. Connect the 115V mains across one of
>them. In effect you're using the primaries as an autotransformer.
>
>The power rating of the transformer that you use should be about twice
>that of the computer you want to run. That gives a reasonable safety
margin.
>
>Another way, which should be safe, but which for some odd reason is
>against the US electrical code is to connect the 220V unit to a 220V US
>outlet - the sort of thing you plug an air conditioner or whatever
into.
>
>It may be possible to modify the PSU. If it uses an iron-core 50Hz/60Hz
>transformer, then look to see if there are 2 primaries wired in series
>for 220V mains. Connect them in parallel for 110V mains - taking care
to
>get the relative polarity correct. I'll not give any more details,
>because it really depends on the PSU design what you should do.
>
>For a switcher, the input circuit is often a bridge rectifier for 230V
>mains. If you can convert this to a voltage doubler, and if there's no
>line-frequency transformer for a start-up supply, then it should work.
>
>A lot of switchers have 2 smoothing capacitors in series - look for 2
>large capacitors of about 470uF at 200V. Connecting the centre-tap of
>these to one side of the mains (after the switch/fuse/filter) will do
it.
>Often there's a link on the PCB (marked 'link for 115V' or something
like
>that) for this purpose. Again, knowing how PSUs work is a great help
here.
>
>But I'd recomend the step-up transformer in your case. It avoids
>modification, and it's safe.
>
>How about a list of useful things for classic computer collectors, even
>for those who don't want to get involved with repair. I'd start with
the
>following... Feel free to add things
>
>A transformer to convert your local mains into the 'other' standard.
I.e.
>a 110V step-down transformer for the UK, a 220V step-up transformer for
>the states.
>
>A composite monochrome monitor, capable of working with UK and US TV
>standards (almost all will do that).
>
>An analogue RGB colour monitor, TV scan rates
>
>A dumb terminal (or a PC + terminal emulator program)
>
>One of those RS232 quicktesters with red/green LEDs. (I use mine more
>than my Tektronix datacomms analyser)
>
>An assortment of cables. In particular IEC mains leads (like PC mains
>leads), RS232 cables (straight and null-modem), video cables (RCA -
RCA,
>BNC, PL259, etc)
>
>-tony
>
>
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Received on Tue Sep 15 1998 - 20:40:40 BST