I live in Germany and there are several stores that only sell American trains and
American 220 volt system.
However, every power supply you will need is available as the suppliers can
ship to any country you may reside. Make sure to go to Rodgau, Germany every other year
for the American train fest--great fun and lots of things for sale.
Just about everything you need to know has been said above. As you did not tell us, whereabouts in Europe you will go to, you have to know, that the UK and continental Europe use different plugs.
Should you need to buy a new wall wart, I can only recommend to do that locally to ensure it has the right plug.
It would help us answer your question if you could tell us specifically what it is you need to power.
Regardless, you have to be mindful of the voltage (110/220 V) but also of the frequency - i.e. US uses 60Hz... pretty much everywhere else (I think) uses 50Hz. Also pay attention to the amperage draw of your equipment and make sure your power supply output is at least that much.
If you need to power a DCC system, check the documentation on your system to see what it's compatible with. If the system is powered by an external power supply (aka "wall wart" or similar to a laptop power supply), check the specs printed on the power supply casing itself. These days, most are designed to accept both 110V and 220V and also accept both 50Hz and 60Hz, and output some kind of DC power. If this is the case with your power supply, it's a simple matter of getting a plug adapter for your German wall outlet, and you're in business.
[edit - I thought you mentioned you were moving to Germany, but I must have remembered that from reading the other thread referenced above]
In my own case, I have an older Digitrax Zephyr powered by a wall wart that requires 110V/60Hz and outputs AC power at 50Hz. I checked the Digitrax website, and found this: http://www.digitrax.com/tsd/KB513/zephyr-non-usa-power-supply/ , so before I moved overseas, I ordered a universal computer power supply from eBay that had a DC output that met those specs. With the appropriate plug adapter, it works like a champ.
If you need to power something that does not use an external power supply (i.e. requires AC power directly from the outlet), the best you can do is get a step-down transformer to convert the voltage from 220 to 110. You'll be stuck with 50Hz power instead of 60Hz, but in many cases that won't matter. Depends on your equipment, though.
Dan Stokes
My other car is a tunnel motor
Good Luck with your move... there has been a fairly full discussion about this recently on http://cs.trains.com/mrr/f/744/t/257179.aspx so depending where you are going, the information should be relevant to you,
Regards from Australia
Trevor
if you wander over to the Electronics & DCC forum you will find this thread
http://cs.trains.com/mrr/f/744/t/257179.aspx
Henry
COB Potomac & Northern
Shenandoah Valley
Depends.
You didn't tell us what you need to power from 240V.
If it is a DCC system with an external power supply, just changing it for a 240V version would be sufficient. Plus you will get the correct plug to fit the outlet.
If you have a Direct current system it may be easier and cheaper just to buy another power pack locally to replace the one you have now. As an added bonus it will be built to and meet their standards.
The other option is a step down transformer, which can get a little costly.
If your equipment has a switching power supply, they often will automatically adapt to their input voltage. All you need is another power cord with the correct plug, or an adapter. Just read the label.
The difference between 50 and 60 Hz is no big deal, so don't sweat that detail.
Need help here, my job is taking me abroad permenently, Volunteerily. I would like to take my layout with me. I found out that all electrical is 220, not 110. I am not the best electrician but I would really appreciate if someone could tell me if I can adapt to 220. I have seen some adapters but they are for lone appliances, etc, hair dryers, toasters, shavers, phone chargers and the such.