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