haapanen@watdcsu.UUCP (10/29/87)
I have been offered a job in Europe that I am contemplating taking for
a few years. If I do take it, I'd like to take my stereo equipment
with me. The problem is, however, that the local electricity supply
is 220V with a 50Hz frequency.
The 220V is no problem, I can solve that with a reasonably inexpensive
500 VA step-down transformer. However, that'll only get me to 110V/50Hz.
Now, this should be no problem for my integrated amp (all DC circuitry,
I think) or my tuner (ditto). No problem with station spacing, either,
since my beloved tuner is analog... My turntable and record collection
will wait for me here, so that's OK, too.
Now, what about the CD player and the tape deck? Everybody I ask (3 audio
stores, 4 manufacturer service depts.) seems to have a different answer.
I would THINK that the CD player would set its rotational speed relative
to a quartz crystal or something, with microprocessor adjustment. Or does
it use the power line frequency (which would cause problems)? If it makes
a difference, it's a Sony CDP-55, about 6 months old.
I am the least confident about the tape deck: I have various answers about
replacing power supplies, new belts, and major adjustments. It's a Sony
TC-FX44, five years old, mid-price (or below) with full logic controls,
but the specs say nothing about the motor type. What kind of motor will
work properly on a different power line frequency? DC motor, servo DC
motor, FG servo DC motor, or anything?
If my current tape deck will not work, I could replace it, maybe. Does
anyone know of a deck that is *known* to work on both 50 Hz and 60Hz?
Any help will be appreciated...
\tom haapanen
{ihnp4,decvax,allegra}!watmath!watdcsu!haapanen
(519) 886-5249pavelz@tekigm2.TEK.COM (Pavel R. Zivny) (11/03/87)
The SONY tapedecks I've seen so far have DC motors; as for the Discman, I am not sure- but I think you can get a battery pack for it - and that would suggest the same. (Or, maybye not a DC motor, but somethig line frequency independent). The definite answer is easy to get- buy yourself the service manuals for your SONY stuff; you can get it from SONY America for about $7 a piece. (Differs slightly for different types of instruments; and no, I don't have the adress with me right now,but I can dig it out if you ask me to) Manuals are neat since you can fix your stuff on your own if you feel like it, and add some features you may miss. (like Automatic Music Sensor from your remote). You may have a slight problem with your receiver anyhow- some parts of Europe are FM in the 60-80 MHz range, for example Eastern Block. However, I'd say if your new job is there,FM reception will be the smallest of your problems. Such is my opinion, and however misspeled you may find it, I like it still the same. pavelz@tekigm2.UUCP (Pavel R. Zivny)
henry@utzoo.UUCP (Henry Spencer) (11/04/87)
> The 220V is no problem, I can solve that with a reasonably inexpensive > 500 VA step-down transformer. However, that'll only get me to 110V/50Hz. > Now, this should be no problem for my integrated amp... Um, beware: the transformer in the power supply is built for 60 Hz, not 50. My impression is that it will sort of work but may have problems with heat dissipation and inefficiency. Anybody here who knows more about this? -- PS/2: Yesterday's hardware today. | Henry Spencer @ U of Toronto Zoology OS/2: Yesterday's software tomorrow. | {allegra,ihnp4,decvax,utai}!utzoo!henry
brian@sdcsvax.UCSD.EDU (Brian Kantor) (11/05/87)
You probably can take your USA (120v 60Hz) equipment to Europe or other places that use 220/50. What you have to watch out for: 1. Convert the voltage. Probably the best way to do this is to get a transformer (or autotransformer - a single tapped at 120 V) to convert the 220 volt supply voltage to 120 volts. You can find these at large department stores, electronic supply houses, and Radio Shack. If you have problems finding one, ask your travel agent for advice. 2. Devices which immediately rectify the mains voltage to DC and use that internally won't care, as long as there is any reserve filtering capacity in the rectifier/filter. Things with switching power supplies such as personal computers probably fall into this category, although SOME of them use the mains as a timebase: see below. 3. Devices which run their mains through a transformer are probably ok if the transformer ran cool in the USA; at 50Hz, the transformer is going to be less efficient, and if it ran hot on 60Hz, it may run a lot hotter on 50Hz. This is iffy - you may just have to try it and see. If you're good at electronics, you might be able to buy a transformer in your new country that will provide the right output voltages. Many devices with transformers have input-voltage adjustment taps that can be set to allow the device to run off various input voltages; 220v may be directly useable on these. 4. Devices which depend on the mains frequency for a timebase are going to be a problem. Synchronous motors in turntables, clocks, interrupt clocks in SOME computers, and things like that are going to run at the wrong speed. Turntables, cassette decks, and other devices that use a quartz crystal timebase won't be affected. Notes: AC fans are often a problem. The motors turn slower, reducing airflow, and some of them overheat the fan motor themselves. Many personal computers use DC fans which won't be affected at all. Most low and medium price cassette decks nowadays use a DC servo motor system for the transport. The speed is independent of the mains frequency, and is set by a potentiometer located in the motor itself - usually tweaked with a screwdriver through a paper-covered hole in the motor. I'm sure I forgot something. Ah well, free advice is worth the price. Brian Kantor UCSD Computer Graphics Lab c/o B-028, La Jolla, CA 92093
des@jplpro.JPL.NASA.GOV (David Smyth) (11/06/87)
You do not have to worry at all about taking 110/60Hz computers and stereos to Europe. TVs don't work, because they have a totally different encoding method. VCRs don't work either. Just buy ANY converter (AC transformer) which has sufficient capacity. I usually go with twice the rated wattage of whatever I'm plugging in. This has worked with CD players, computers, plotters, stereos ... again, NO PROBLEM
dje@datacube.UUCP (11/09/87)
Did you check the nameplate? If it says 47-63 Hz or 50-60Hz, you're definitely safe. If it says 60Hz, you may not be. Dave Erickson ---------------------------------------------- ------ Datacube Inc. / /| 4 Dearborn Rd. ------ | Peabody, Ma 01960 || \| | ihnp4!datacube!dje || /|/ Human:(617)535-6644 ------ Fax: (617)535-5643
KEN@ORION.BITNET (Kenneth Ng) (11/18/87)
>From: henry@utzoo.UUCP (Henry Spencer) >> The 220V is no problem, I can solve that with a reasonably inexpensive >> 500 VA step-down transformer. However, that'll only get me to 110V/50Hz. >> Now, this should be no problem for my integrated amp... > >Um, beware: the transformer in the power supply is built for 60 Hz, not 50. >My impression is that it will sort of work but may have problems with heat >dissipation and inefficiency. Anybody here who knows more about this? >PS/2: Yesterday's hardware today. | Henry Spencer @ U of Toronto Zoology >OS/2: Yesterday's software tomorrow. | {allegra,ihnp4,decvax,utai}!utzoo!henry Using a 60 Hz transformer at 50 Hz will probably be ok, the opposite might not. Heat generated by the transformer is a function of the 'area' of the hysterious curve multiplied by the frequency. Therefore the lower the frequency the lower the heat production. But, just to be sure, if it gets too hot to leave your hand on (and your not one of these Indian yogis), its generally not wise to use it.
jj@alice.UUCP (11/19/87)
In article <63KEN@ORION>, ken@orion.bitnet.UUCP writes: > Using a 60 Hz transformer at 50 Hz will probably be ok, the opposite might > not. Heat generated by the transformer is a function of the 'area' of > the hysterious curve multiplied by the frequency. Plus, the heat generated by resistive losses in the windings, which could be remarkably severe if the transformer, designed for 60Hz, just happens to saturate at 50Hz. The resulting inrush, which would certainly nuke fuses at least, might also create some spikes that would cause trouble downstream of the transformer. The eddy current losses go up with frequency, yes, but the maximum voltage-time integral goes up with decreasing frequency, and is what determines the saturability of the transformer. Even if it doesn't saturate, you can get out far enough on the BH curve to cause more losses and funny waveshapes/etc in the secondary that can cause lots of excess heat. -- OPUS FOR PRESIDENT IN '88, TEDDY BEARS SUPPORT THE MEADOW PARTY! "...Kulimani, Kulimani sizwe! ..." (ihnp4;allegra;research)!alice!jj HASA, A+S divisions, H tendencies. Copyright JJ 1987. All rights to mail reserved, USENET redistribution otherwise granted to those who allow free redistritution.
dmt@ptsfa.UUCP (11/19/87)
In article <63KEN@ORION> KEN@ORION.BITNET (Kenneth Ng) writes: > >Using a 60 Hz transformer at 50 Hz will probably be ok, the opposite might >not. Heat generated by the transformer is a function of the 'area' of >the hysterious curve multiplied by the frequency. Therefore the lower >the frequency the lower the heat production. But, just to be sure, I thought it was just the opposite: it is ok to use a 50 Hz transformer at 60 Hz but not the reverse. A low frequency transformer requires more iron than a high frequency one. That's one reason they started using 400 Hz in aircraft. The current in any inductor is limited by the inductive reactance. Lowering the frequency will lower the inductive reactance and increase the current and the amount of heat produced. Lowering the frequency to the extreme 0 Hz (DC) is generally not recommended for any transformer. The DC resistance of the windings is low and the current will be very high. Increasing the frequency will have the opposite effect. The inductive reactance will be higher and the current lower. Heating is due (in part) to I^2R losses, IR (eddy currents), and hysteresis losses. Eddy current and hysteresis losses increase rapidly with frequency but ordinary iron cores are good up to about 15,000 Hz. -- Dave Turner 415/542-1299 {ihnp4,lll-crg,qantel,pyramid}!ptsfa!dmt
dhesi@bsu-cs.UUCP (11/20/87)
In article <63KEN@ORION> KEN@ORION.BITNET (Kenneth Ng) writes: >Using a 60 Hz transformer at 50 Hz will probably be ok, the opposite might >not. Heat generated by the transformer is a function of the 'area' of >the hysterious curve multiplied by the frequency. Therefore the lower >the frequency the lower the heat production. Please, somebody correct me if I am wrong. A long time ago I wound several transformers. Without knowing the theory, but simply consulting some reference books, I discovered that the bottom line was that the higher the frequency the fewer turns one needed to create an intense enough magnetic field. Based on this, I conclude that if one uses a 60 Hz transformer at 50 Hz, there will be greater resistive losses and greater heat production. Simple extreme example: go from 60 Hz to 1 Hz. Most of the current will cause heating, unless you increased the number of turns in the primary to compensate for the decreased magnetization of the core. The question is then whether the heat generated in a transformer is mostly due to hysteresis loss or due to resistive loss. I won't even try to guess. -- Rahul Dhesi UUCP: <backbones>!{iuvax,pur-ee,uunet}!bsu-cs!dhesi
fab@faline.bellcore.com (Fabrizio Grandoni) (11/21/87)
+From ken@orion.bitnet.UUCP Wed Nov 18 06:02:08 1987
+>From: henry@utzoo.UUCP (Henry Spencer)
+>> The 220V is no problem, I can solve that with a reasonably inexpensive
+>> 500 VA step-down transformer. However, that'll only get me to 110V/50Hz.
+>> Now, this should be no problem for my integrated amp...
+>
+>Um, beware: the transformer in the power supply is built for 60 Hz, not 50.
+>My impression is that it will sort of work but may have problems with heat
+>dissipation and inefficiency. Anybody here who knows more about this?
+
+Using a 60 Hz transformer at 50 Hz will probably be ok, the opposite might
+not. Heat generated by the transformer is a function of the 'area' of
+the hysterious curve multiplied by the frequency. Therefore the lower
^^^^^^^^^^
+the frequency the lower the heat production. But, just to be sure,
+if it gets too hot to leave your hand on (and your not one of these Indian
+yogis), its generally not wise to use it.
Sorry, it's quite the opposite: a 60 Hz transformer can have serious
problems (burning out...) at 50 Hz. While Ken's argument is correct,
the strong nonlinearity of the hysteresis [nothing in common with
hysterical :-)] gives raise to another effect, which can be dominant:
the lower frequency requires proportionally higher peak magnetic flux
to cope with the applied voltage; if the transformer was designed to
work near saturation @60 Hz (to spare on magnetic material) the need
for more flux will drive the magnetic core deeply into saturation.
This means that: 1) the area of the hysteresis curve increases; and
2) the magnetizing current rises easily beyond limits allowed by thw
wire section. Both effects result in overheating the transformer.
But it's good engineering practice to leave adequate safety margin in
the design, i.e. not to exploit the magnetic material to the limit of
saturation; so normally everything should be OK. Unfortunately the
transformer specs (when available) don't help to get the above
information; so all you can do is: a) buy a transformer from a trusted
manufacturer; b) test it yourself (isn't any place over there where you
can find 50 Hz power?).
As last note, remember that the same arguments apply, of course, both
to the external step-down trasformer and to any transformer
used _inside_ the device (ampli, etc.); so, the first
time you'll use it @50 Hz, watch the smoke...
__
Fabrizio Grandoni _/ /_
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IEI-CNR Pisa //////
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