Method for operating a permanently excited synchronous motor of a hand-held working device, and hand-held working device

A hand-held working device, comprising:

• a user-operable operating element;
• a permanently excited synchronous motor without a magnetic sensor;
• and
• a processor implemented control device configured to carry out the acts of:
• a) sensorlessly determining a position variable (POG) representative of a position (PO) of a rotor of the synchronous motor at a standstill;
• b) determining a direction variable (RIG) for a continuous rotation of the rotor from standstill in a direction (RI) on the basis of the determined position variable (POG) such that an absolute value (BDM) of an attainable torque (DM) that can be generated by the synchronous motor during sensorless actuation for the rotation in the direction (RI) is greater than an absolute value (BLM) of a breakaway torque limit (LM) of the working device;
• and
• c) sensorlessly actuating the synchronous motor on the basis of the determined direction variable (RIG) for the rotation in the direction (RI),
• wherein the sensorless actuating is initiated via operation of the user-operable operating element.

A method for operating a permanently excited synchronous motor of a hand-held working device, the method comprising the steps of:

• a) sensorlessly determining a position variable (POG) representative of a position (PO) of a rotor of the synchronous motor at a standstill, wherein the synchronous motor does not have a magnetic sensor;
• b) determining a direction variable (RIG) for a continuous rotation of the rotor from standstill in a direction (RI) on the basis of the determined position variable (POG) such that an absolute value (BDM) of an attainable torque (DM) that can be generated by the synchronous motor during sensorless actuation for the rotation in the direction (RI) is greater than an absolute value (BLM) of a breakaway torque limit (LM) of the working device;
• and
• c) operating a user-operable operating element to sensorlessly actuate the synchronous motor on the basis of the determined direction variable (RIG) for the rotation in the direction (RI),
• wherein steps (a) and (b) are carried out without a rotation of the rotor.