Travel voltage converters..

Hey guys,

Goin on a trip soon,and picked up a couple of international voltage converters. 240->120V. They say they are rated 50W and 1600W. What's up with the dual rating? Maybe 50W max for electronics,and 1600W max for resistive loads (hair dryers,coffe makers,etc) ? Pretty big jump in the numbers.

These particular converters are small,REALLY small.. I assume it's some kind of switching converter,or something. I know the old ones used transformers,these obviously don't -they're the size of a small box of matches,with prongs out one side,and holes in the other.They weigh..Pfft..a couple grams maybe?

Any idea what's in these things? Maybe a triac circuit of some kind? (not much room inside!)

There is a warning against using it for laptop computers,and other similar items (which is what I wanted to run from them! Doh!) Dare I risk it? (New laptop,PSP,cellphone charger,etc,etc.) I'm not sure the 50W rating would be enough for the laptop anyways. Bah! Guess i've got to find a 'transformer' type converter either way.

Reply to
phatty mo
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Perhaps that's 50W one way around and 1600W the other way around?

Got a make and model number? URL?

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A device the size you describe will NOT do the job you want.

Are you sure your electronic devices can run on both 120 or 240? Many modern devices run on either automatically, others have a switch.


Reply to
Dan H

Check the specs on your laptop power supply - it may handle 120 or 240 volts (the Acer supply I have here does.) If so, you don't need any converter for it, just a connector adaptor.

Peter Bennett VE7CEI 
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Reply to
Peter Bennett

The switching converters I've seen were larger than that and mostly heatsink, the only matchbox sived ones were plug adaptors only and not voltage converters

many laptops and mobile phone chargers are built for both 230 and 110 V part of them being portable personal devices... PSP may be a problem being more of a toy...

Bye. Jasen

Reply to
Jasen Betts

This is basically what that it.

The technology of those 50W and 1600W converters is very different.

The 50W converter designwed for electronics in mind (works with practically everyting that is within converter power rating) is a step-down transformer. The output of it is sinewave as incoming power. The size is limited how small you can that

50W full transformer or auto-transformer make.

The 1600W converter can be though as a light dimmer set to some center position. They will just pass the the part of the incoming sinewave to the output. The average power of that crude waveform represents the heating power the

110V AC would give. The wavefrom is not sinewave, the peak voltage getting to device is typically mich higher than with real 110V power etc... This kind of converter works well on simple heating loads etc.. which do not care of incoming power wavefrom etc.. This kind of converter is not suitable for electroni devices, transformer powered devices etc... serious equipment damage can happen. In this type of converter you just need quite small amount of component. Some control circuitry (few disretes and/or one IC) plus the power switching component (triac, FET, etc.) with suitable heatsink. If you use triac for switching, with 1600W load, the power loss on the triack would be possibly in 10-15W range... With a low resistance FET maybe considerable less power loss.

Those 1600W converters canbe though as very crude switching converters.

I think they have a triac circuit pretty similar to normal light dimmer.

I don't recommend. Can become an expensive experiment.

50W rating is not enough for modern laptops. The universal car adapters for laptops nowadays have power rating in 60-120W range. Look for you computer manuals how much it consumes (check also markings on power supply). And then select a suitable transformer.

And also when you read the manual, check also if your computer power supply is universal. I have seen many laptop power supplies that have for example 100-240V input voltage range. If your laptop power supply is this type, then you can plug it directly to 240V.

If your laptop power supply can't accept 240V voltage directly, then you need a suitable converter: transformer 240V->120V.

Other option to check is getting a new power supply for the laptop, one that works on all voltage you need to use it with. And then just a cord/adapter set that allows you to plug it anywhere you need.

Tomi Engdahl (
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Tomi Holger Engdahl

Okay,well it appears that everything uses a "universal" SMPS 120 or

240Vac input. So,I guess all I need is a plug adapter or two..But,where to find them?

The cheap little ones we grabbed while looking for luggage at Target.

(ack long URL) I didn't expect them to be great,or to work with everything..but figured what the heck,they were on sale,and got a couple anyways,just incase.

I'm now off to radioshack to get thier 85W model here:

It appears to be "electronics safe"..I just hope that 85W is enough for the laptop.Everything else is small,a dozen or two watts at most. The laptop is a newer Dell? I think,it's pretty small.I've no details cause it's technically not mine,and not here with me at the moment (hence why I don't want it to explode!) I assume it has a 'universal' supply also.

Would Radio Shack carry 'adapter' plugs/cords to convert Euro-style plugs (in Spain) to a US '2-prong' plug, *without* the converter part? I havn't found any as of yet,and i'm wondering if they're even made.. Could be a big problem/liability if someone plugged in the wrong thing! Guess I'll find out if RS has them,I'm off to there now..

Thanks for the input guys!

Reply to
phatty mo

Be very careful using a travel converter that is not a real transformer. The electronic ones damage a lot of equipment. Also, take care that whatever you run in Europe that is from America, can tolerate the 50 Hz. Many devices have been damaged by both these solid state travel converters, and from using them on the 50 Hz mains, when they were designed for 60 Hz only.

Jerry G.

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Jerry G.

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