We have to be totally honest here:
These transformers are of the "autotransformer" type, which means that it has one coil. The 110V is tapped half-way the coil. This is a clever solution as it will gain you half of the input voltage, while you only need one coil, and thus reducing costs.
PLEASE NOTE THAT _ALL_ COMMERCIALLY AVAILABLE CONVERTERS ARE CONSTRUCTED THIS WAY !!!!
It's not bad, but there is one small but:
In the _extremely_ unlikely event that the transformer fails internally, you COULD get the full input voltage on your output.
The chance of winning the lottery is probably higher, but I still would like to mention it. Transformers VERY rarely fail and mostly because they've been run on MORE than their specced load. (Getting very hot).
The alternative is a much more expensive "traditional" transformer with two coils which totally separates the two circuits, but as mentioned, these are quite some more expensive.
Again, the Minwah's that were mentioned before on another thread are constructed in the same way (single coil) so these have the same risk. If you feel that a Chinese brand might show up a problem like that sooner than a Dutch professional quality product is entirely up to you
A second consideration: one of the leads of the input voltage is directly conneted to the output. In countries where you cannot reverse a mains connector, that's not a big deal because you can set-it up so that it will connect the 0 wire instead of the phase (the one that holds the voltage). However, in Europe we can reverse the mains plugs at will. This is STILL no problem IF double-pole switches are used. However, since we got a load of US built machines I think there's a chance that they used single pole switches. The result could be that there is still 230 V potential on your machine if you turn it off.
Again, nothing major here, but something to at least think about when installing them.
