How do International power converters work?

[charlie b]

In a few weeks, my wife and I are taking a trip to Newcastle (North of London). I will bring my electric shaver, a charger for my camera, and a notebook computer. I have to go buy a converter, so that these items can be used on the UK?s 230 volt, 50 hertz system. I have to believe they do more than change the shape and orientation of the plug?s contacts.

I would like to know what is inside these converters. Is it just a transformer, to get from 230V to 120V? If so, then the power remains at 50 hertz. Can that harm a notebook computer? The ones I have seen appear to me to be too small to contain the electronics and other stuff necessary to convert both voltage and frequency. Are there choices of models with different levels of complexity, from the $5 model to the $25 model to the $125 model?

 

[boater bill]

My experience is they are just transformers. Check to see if your equipment can operate at 50Hz.

Funniest story using these, my wife hated the 'no' blow hotel hair dryers at the hotel in Venice. Plugged in her converter, started drying away, until the entire floor lost power when she caused the main to trip! Didn't think it would be that much of a problem, guess I was wrong.

Your laptop should be OK but I would check the frequency. You may be able to buy a European power cord if you have a brand name laptop.

BTW, have fun

 

[kingpb]

I was curious so I actually read my laptop book, it says the power adapter I have is good for 47 - 63 Hz, and 90-135 Vac and 164 -264 Vac. Output is Dc so the laptop itself is safe.

When all else fails, read the directions. What a concept!

 

[msb10]

I had just this experience, with exactly the same appliances, when I went to Spain a couple of weeks ago. I had to leave in a hurry, and I didn't have a chance to pull together a converter. I asked my brothers (who both live in Europe), and they both tried to hand me a "converter" that was really just an adaptor (so far as I could tell); in other words, it was a molded plastic dingus with a female two-prong outlet for a US 120V plug, and the other side had a pair of round pins that fit in the 240V single-phase outlets that they have in Spain. I understand that these outlets are fairly standard in most of Europe (for example, in Paris, where one of my brothers lives). I was a little suspicious, but (like kingpb says) I looked at the power supply for each of these, and they all said input 100-240V~, 50-60 Hz. So I picked the picked the thing I figured I could get by without, plugged it into the adaptor, and plugged the whole thing into the wall (actually, I made Josh plug it into the wall), and the little green light came on that told me it was charging. So, chances are, you can look at your nameplate, and you'll be o.k. out of the box.

Good luck, and have a safe trip.

Matt

edited for spelling mb

 

[sandsnow]

We went to Audtralia five years ago. It's 220 over there. I bought a converter, the highest wattage I could find. When we got there I noticed that something my wife had was rated up to 220, I think it was the hair dryer. It worked plugged into 220, but it did seem like it got a little too warm. Still works to this day.

 

[LarryFine]

There are two types of converter. (Well, three if you count the simple prong adapter described by Matt.)

The first one is actually a step-down transformer, used with electronic devices, and the second is merely a high-current diode that results in a half-wave output, used with heating-type appliances.

Always check the voltage range of your devices; most computer power supplies don't require a voltage adjustment, as Matt discovered.

 

[msb10]

Just another comment, my shaver was marked the same way (100-240V, 50-60Hz). Though the one that I have may have been originally designed for the European market (the name sounds German, anyway), I suspect many similar appliances are the same way.

Matt

 

[sparky59]

how do international power converters work?

how do international power converters work?

why doesn't the usa have the more efficient 220v system?

 

[LarryFine]

why doesn't the usa have the more efficient 220v system?

We do. It's simply center-tap-grounded, which results in a safer lower line-to-earth voltage.

 

[kingpb]

why doesn't the usa have the more efficient 220v system?

Perhaps you could explain why 220V is more efficient, Thanks.

 

[charlie b]

Perhaps you could explain why 220V is more efficient, Thanks.

Less current, less line loss. But at the household voltage level, that factor is insignificant.

 

[charlie b]

Thanks for the replies, everyone. But part of this question has just become moot. Based on recent aircraft security threats, I've decided not to bring the notebook (I would not want to check it with my baggage). So instead of using it to download pictures (which would allow me to reuse the camera memory cards), I am just going to buy more camera memory cards.

 

[boater bill]

Have your laptop shipped via DHL to your Hotel. And have the extra memory cards as backup.

 

[sparky59]

ok....humor me with one more question. Wouldn't you have more available watts on each circuit? And therefore a smaller space panel,fewer breakers and fewer home runs with a 220 system?

 

[LarryFine]

ok....humor me with one more question. Wouldn't you have more available watts on each circuit? And therefore a smaller space panel,fewer breakers and fewer home runs with a 220 system?

If conductor size is the only concern, then yes, the higher voltage is "more efficient". We move up in voltage for heavier appliances to reduce the current required, but the voltage-to-earth stays the same for either voltage.

On 220v systems, the voltage-to-earth is higher, which does indeed reduce the current for a given power level. However, as with everything else, there is always a trade-off. Why don't we use 10KV?

For a given amount of work, a certain power is required. Whether that's high voltage at low current or low voltage at high current, the wattage is the same. Therefore, transformer size will not vary, only the turns ratio.

Obviously, high-voltage transmission lines are used for economical reasons, as well as less voltage drop (and I^2R power loss). Insulation is generally cheaper than conductor, to a point, but we drop it for safety reasons.


(By the way, that was two questions.)