berger@andromeda.RUTGERS.EDU (Theresa Berger) (08/14/86)
A student here is planning to purchase an IBM-PC and use it in both the U.S.A. and in India. He wants to know what sort of voltage a/o frequency converter he needs so that he can use it in India, and where such a beast can be obtained. He knows that both power-line voltage and frequency have different values in India, but he does not know the specifics. My usual sources at IBM don't have time to pursue such an esoteric question. Any information would be appreciated, but, just to make things interesting, our local systems will be down for maintenance for the next few days. Please send information to LATZKO@CAIP.RUTGERS.EDU. Thanks. T.B.
kdale@BBNCC-EUR.arpa (Keith Dale) (08/14/86)
My apologies for the reposting, but the return path won't work.
To latzko@caip.rutgers.edu:
The attached message was posted on the net a short while ago - I don't know if
you've already seen it, but here it is anyway. I have no earthly idea what the
power is in India, but I wouldn't be surprised if it's 220 V/50 Hz; thus, this
message might be relevant. Good luck!
From: Ross Alford <alford%ecsvax.uucp@BRL.ARPA>
Newsgroups: net.micro
Subject: using US electronic equip on 220v (summary)
Date: 15 Jul 86 02:02:27 GMT
To: info-micro@brl-vgr.arpa
Several weeks ago I posted a note asking in general about what problems
might exist in running electrical and electronic equipment designed for
110v 60Hz AC on the 220v 50Hz AC that exists in many other countries.
Quite a few people responded in netnews, and I thank you for the effort.
Several more responded via mail, and were also very helpful. Their
responses, edited to remove identities and extra lines but otherwise
intact appear below.
I hope that no-one who responded via mail is offended at not being credited:
in fact, it was deciding what to do with attribution of the mail responses
that delayed my followup posting. I finally decided that removing identities
is the lesser evil: if someone wanted to respond publicly, they could have
done it in news. Thanks to one and all again...I have a much better feeling
for the problem now, and am going to buy 2 or 3 step-down transformers.
net responses follow:
--------------------------
Note one other problem you might have, the power connectors
vary from country to country so besides the stuff below you need
adapters so you can plug it in.
There are about three classes of devices you have to worry about,
1) voltage dependent devices 2) frequency dependent devices and
3) waveform dependent devices.
Class 1) are things like heaters or light bulbs, here as long
as the voltage is about right they don't care even if they get DC.
The little converter devices work for these.
Class 2) are devices like constant voltage transformers which
are resonant at 60Hz. For these 60 Hz is an absolute requirement and
at the correct voltage. Not much hope for these they must have
120V 60 Hz, but this kind of stuff is rare.
Class 3) are things with transformers. Here you have to have
the voltage about right and it should be a sine wave or the transformer
gets very warm. A stepdown transformer will usually make these work.
Sometimes the little converters just put a diode in the AC line
and this gives you funny shaped waves that are ~ 120V high. Here lightbulbs
and things with AC/DC motors (like shavers) would do just fine. Things
with transformers would not work at all since the waveform has a net DC
component and transformers are sort of DC shorts.
Most modern electronic equipment like computers have switching
power supplies and in a lot of cases all you have to do is move a
jumper, get a new power cord and it works just fine at 220 V 50 Hz.
With one exception this works, if the fan in the box is 120V 60Hz it
won't be too happy. In this case a stepdown transformer (very easy to
find in Europe) would work OK. The fan would run 1/6 slower but the
switching power supply would be happy 50 Hz. Equipment designed for use
on both sides of the Atlantic usually has D.C. fans driven from the main
switching power supply, here moving the power supply jumper also takes
care of the fan so everything works.
For small transformer stuff like chargers you have to run them
from stepdown transformers but they have no trouble with 50 Hz. Chargers
from folks like HP and others sometimes even have a 120/220 switch built
in them. You still need an adapter so you can plug them in but no
step down transformer.
On monitors I have no personal experience but from doing the
opposite (using European Monitors here at 60 Hz) it will probably work.
You will need stepdown transformers for the monitors .
---------------------------
I can tell you that my NiCad battery charger (110 volts) works just
fine off of a bottom-of-the-line Radio Shack voltage converter plugged
into the local 220v/50hz. Also my contact lens sterilizer (heater type).
Those are the only plug-in devices I brought with me, so I can't help
you with anything else.
---------------------------
My experience, based on using a KayproII and a Compaq in Germany
and talking to other people in similar situations:
Ignore the cycle difference. Everything is being converted to
DC first, so only the voltage difference matters. You can't use
the inexpensive light-weight converters. You need a step-down
transformer, obtainable locally abroad if not here. Better yet,
buy dual-voltage equipment!
---------------------------
Seeing as I've been living in Germany for the last 2 1/2 years with a pile of
110v/60Hz stuff in my house, maybe I can shed a little light. Little stuff
like AC/DC converters or battery chargers -no problem. I've been running them
off of a 1000W step down transformer (with an outlet expander) alongside my two
VCR's (110/60), Sharp TV (110/60) and various other gizmos. As far as I know,
the only things that you have to beware of are AC motor appliances (fans and
clocks) and electronic devices that use the AC frequency for timing - some
computers fall into this category, but NOT very many. The only thing that 50
Hz would do to a monitor set for only 60 HZ is make it flicker. Wait. Let me
ammend that: I'm sure that there are *some* monitors somewhere that would have
real problems with 50 Hz. Better to check on the specific monitor first. Some
of the color monitors, though, are "smart" and accept any input voltage and
frequency - IBM Color Monitor is one of them. Last item: I have seen a 110/60
printer running off of a stepdown transformer/50 Hz burn out its printhead;
however, the owner had it running for 6 hours a day *continuously*. It is
recommended that your printer be set for 50 Hz, though.
P.S. - About the travel converters: I've never used them, so I don't know. It
seems to me that I remember some mention of the (alleged) fact that the heavier
stepdown transformers offer some sort of line filtering and/or minor surge
suppression. All I know is that whatever you use, you should plug in the
transformer, turn it on, plug the devices into the transformer, then turn on
each device. NEVER use the transformer as a power-on switch for your entire
setup or a nice, fat surge could zap everything. That's all...
---------------------------
It would take great skill and dedication to design a simple battery
charger that would work at one frequency and not the other, so that
would probably work fine. It is my understanding that most video
monitors use the line frequency to generate either driving voltages
or synchronization signals or both, so there could well be a problem.
You might still get a picture, but with something wrong with it.
I don't know whether or not there is any risk of damaging the monitor.
Makers of computers and monitors for use in Europe usually make versions
compatible with a European broadcast standard (i.e. PAL, which uses a
50 Hz field rate). Regulated power supplies may be affected by requiring
larger capacitors for a given level of ripple. Devices containing
electric motors are normally frequency-sensitive, unless you are sure
the motors are running on filtered DC. Your best bet for any doubtful
piece of equipment is to contact the manufacturer or find a
knowledgable sales representative.
---------------------------
Usually 60Hz appliances will work with 50Hz current. Small electronic
appliances will usually work since most of them convert the current to
DC. TV's and monitors have a much higher probability of not working.
---------------------------
I am writing to you in hopes that you will not make the same mistakes I
did, I have discovered things the hard way.
Quite frankly Franzus stuff (expletive deleted)! To answer your question, no.
The Franzus converters use a SCR to try to tame the voltage down from 220 to
110, but they dont give you the full wave form of ac current, only half.
I blew out a stereo amp and a CD player. It appears that the things most
affected are semiconducter devices. I strongly recommend that you avoid
this type of converter.
I cannot answer this question exactly but I know that *some* monitors look
to the line freq, but most donot. Almost In every machine I can think of,
the input current is rectified (made DC) and from there on talk of freq is
meaningless.
The types of machines that 50/60 Hz does make a difference on is those
with AC motors in them, these *will* burn out with time if you use them on
50 Hz.
FYI: I am using an AT in the 220V/50Hz mode (red switch in the back) that
originally came from the US. But I am using the monitor (EGA) on a Step-down
transformer, as there was no easy way to change the voltage requirements.
Note that the transformer will *not* change the frequency.
Pay the money, you'll be glad you did...
--------------------------
Again, I thank everyone who responded. This was the most helpful set of
responses I've received to a question asked on the net.
Ross Alford
...mcnc!ecsvax!alford
Disclaimer: The opinions expressed above are not those of my employer or
of NCECS. They aren't even mine--I'm just relaying them.
--------------------------
And my thanks to Ross Alford for posting this summary in the first place. I've
used this message quite a few times already to convince people that's it's safe
to bring their pet PC to Europe.
Keith <kdale@bbncc-eur.arpa>jsm@vax1.ccs.cornell.edu (Jonathan Meltzer) (08/15/86)
In article <532@andromeda.RUTGERS.EDU> berger@andromeda.RUTGERS.EDU (Theresa Berger) writes: > > A student here is planning to purchase an IBM-PC and use it in both the >U.S.A. and in India. He wants to know what sort of voltage a/o frequency >converter he needs so that he can use it in India, and where such a beast can >be obtained. He knows that both power-line voltage and frequency have >different values in India, but he does not know the specifics. My usual sources >at IBM don't have time to pursue such an esoteric question. Any information >would be appreciated, but, just to make things interesting, our local systems >will be down for maintenance for the next few days. Please send information to >LATZKO@CAIP.RUTGERS.EDU. Thanks. > T.B. Theresa, My project leader is currently in India with an IBM PC Convertible. He was told by Indian contacts that the standard convertible power pack would run on Indian current. I'll know in three weeks if that was true and if other IBM accessories are available in India. Respond to this via net.risley. Jon Meltzer Dept. of Modern Languages and Linguistics, Cornell University ------------------------------------------------------------------------ "Disclaimer" is a trademark of Bell Laboratories.