{HEAD ~ Variable pulses} of an electric voltage are applied to the electric motor in {TAIL ~ such a way} that the rotor of the electric motor moves at a rotational speed which can be set 
are applied in
{ HEAD ~ Variable pulses } of an electric voltage are applied to the electric motor in { TAIL ~ such a way } that the rotor of the electric motor moves at a rotational speed which can be set
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH