@DLane Thanks for your answer and suggestions. It appeared it was not so easy to get appropriate transformer in Poland. The only ones still on sale had to low amperage. I found appropriate AC/AC in Germany (amazon.de), but… they do not deliver anywhere outside, 'cos they do not handle international VAT. Grrr…
Fortunately my boss works in Germany and will bring me one transformer in a week time. Good 'cos starting from tomorrow we shall have above 30 degrees Celsius.
@sbarnhard thanks as well. Actually I found help in the international category (I mentioned it in my first post, someone from New Zealand had a problem), but I do not know how to make my posts to fall into that category.
Thanks guys and cheers,
s