Voltage conversion - US to EU - converters didn't work
I recently purchased a trimming machine from the US during a business trip, and I brought it back to Europe (Switzerland) where we have 230 V - 50 Hz. The machine has on top "120V ~ 60Hz 9W". I used 2 different voltage converters which read "INPUT 200/240V 50/60Hz - OUTPUT 100/120V 50/60Hz - MAX 100W" however I am not able to use the machine properly and it makes insane sound and work very fast/overheats. What am I doing wrong?
Thanks in advance.
Emmanouil