Date   : Mon, 21 Nov 1983 10:29:00-PST
From   : ABN.ISCAMS@usc-isid
Subject: Transformers and European Current

Netland:

My organization has been using some big heavy lunkers of Solas "constant
voltage" transformers for years now to stabilize some of the horrible AC
current we get under field conditions (Army generators, long cables running
through mud, strangers hanging coffee pots and arc welders off the line, etc.)
They've worked just fine with the usual 110V AC (+/- 20 volts), and also
worked fine when I grabbed some three-phase 220.  (Had to jumper them up
internally for the 220-110 conversion, but they're designed for that.)

Problem:  Went to Germany.  Took the good old Solas's along (they convert
220 to 110, don't they?).  Plugged in (appropriately jumpered to 220>110
conversion).  Got a beautiful, steady spikeless 96 volts!  Huh!
Found an already-transformered 110 wall plug.  Rejumpered friend Solas, now
110>110 range. Plugged in.  Got a beautiful, steady spikeless 96 volts!

Reinvented the theory of AC transformers, and I need some feedback from
you real electrical/electronics types out there (I'm a mere SF weapons man).
I propose the core of a transformer vibrates from the AC cycles, or in some
way creates a cyclic magnetic field.  This magnetic field is cut by the 
windings, thus creating the output AC voltage.  (Kind of like an alternator
does, but the field moves instead of the windings.)

The 50 cycle current available in Europe cycles the magnetic field slower,
thus resulting in a reduced output AC voltage.  (The 110/96 ratio is
suspiciously close to the 60/50 cycle ratio, prompting me to this hypothesis.)

Could this be right, wizards?  Any way to cobble my trusty old Solas's up
to kick that output voltage up (and no, I ain't gonna rewind that sucker
either!)?  Or just buy European 220/110 transformers with the cycle difference
already accounted for?

Anyway, lesson learned for you guys planning to go to Europe:  don't depend
on any Stateside 220/110 transformers working correctly.

(Incidentally, the Apples I was using ran just fine on 96V.  Two of three
Corvus 20Meg hard disks ran fine (last one wouldn't run there; ran just
fine back Stateside).  Sanyo color monitors - just fine on 96V.  Sanyo
green screen monitors:  yuck!  Extremely blurry characters top and bottom
of screen; totally unsatisfactory.  Took a chance, grabbed the available
110 volt wall current, ran it through an isolator (really had dirty current
at that location); green screen ran fine.

Oh, yeah, blew up three (count 'em, 3) Global OOPSes (Uninterruptable
Power Supplies) trying to run them on the available 110V wall plugs.
Capacitors catastrophically destructed (really neat, lots of smoke
and expensive smells).  Lost two solid and one wet capacitors -- the
wet one on the electronics board blew like a minigrenade, plastering
bits of foil and gunk all over the board and actually blowing several
traces off the board!  Suspect the 110V in that building was obtained
by "cycle clipping" (donno the real word for it, but you clip off one
side of the 220V cycle, getting 110V all right, but a strange 110V
that maybe electronics don't like so very much).  One of the OOPSes
ran OK for a couple of hours on Solas-transformed 220>96V, and then
started complaining; so we never did get any use of our OOPSes.

'Nuff said on my experiences.  Would appreciate some hints/suggestions/
background knowledge on European power and my hardware.

Thanks in advance,

David Kirschbaum
SGM, USA
Corps Automation Management Office
HQ XVIII Abn Corps, Ft Bragg