Does not 50 Watt

This transformer does not deliver what it promises: 10 LED lamps with a total of slightly more than 15 watts can not operate so that when they are all connected at the same time. If you, however, only 5 turns and then (secondary side) for another 5, the device packs the readily. LED lamps with 12V have a rather high, very short inrush current. This means that short-term basis (ie some ms!) More than 50W necessary and thus comes the device to vibrate and the lights flicker only.
Way: On the secondary side half of the lights off.
But I do not see any special transformer for LED bulbs!
I run the lamps now with the good old magnetic transformer with 2 Zenerdioen on the secondary side, goes perfectly.