Automatic cross wound bobbin winder has a sensor to monitor at least one yarn parameter for the signals to be compared with set values to reduce the motor speed accordingly for an optimum winding speed

To optimize the bobbin winding speed, at an automatic bobbin winder for cross wound bobbins, parameters are registered for at least one characteristic of the yarn dependent on winding speed to be compared with preset values which cannot be tolerated further for this characteristic. The result is a reduction in the winding speed by slowing the rotary speed of the drive motor. When it is detected that the given value has been achieved, the motor speed is reduced by a preset rotary speed value. The registered parameter is the hairiness of the running yarn. An Independent claim is included for an appts. with a sensor (19) to register at least one yarn characteristic, connected to an evaluation unit. The evaluation unit compares the sensor signal values with given values. When the sensor signals achieve the given value level, a signal is generated to reduce the motor (14) speed. Zum Optimieren der Spulgeschwindigkeit einer Spulstelle eines Spulautomaten werden Kennwerte wenigstens einer von der Spulgeschwindigkeit abhängigen Eigenschaft des Fadens erfaßt und mit vorgegebenen, nicht mehr tolerierten Werten für diese Eigenschaft verglichen. Wenn die erfaßten Kennwerte die vorgegebenen Werte erreichen, erfolgt ein Reduzieren der Spulgeschwindigkeit mittels Verringern der Drehzahl des Antriebsmotors.