Abstract: An electronically commutated motor is operated from a DC voltage source (UB), e.g. from a DC link circuit (46). The motor has a permanent-magnet rotor (28) and a stator having a stator winding strand (26) in which, during operation, an alternating voltage is induced by the permanent-magnet rotor (28). It further has an H-bridge circuit (22) having power semiconductors (T1 to T4). At the beginning of a commutation operation, the presently conductive semiconductor switch of a first bridge half (38) is switched off, in order to interrupt energy delivery from the DC voltage source (UB), so that, in the other bridge half (56), a loop current (i*; ?i*) flows through the stator winding strand (26), through the semiconductor switch still controlled to be conductive therein, and through a recovery diode (58; 60) associated with the blocked semiconductor switch of that other bridge half.

Abstract: A fan arrangement has an electric motor (18) that serves to drive a fan wheel (26; 170) and that has an internal stator (44) and an external rotor (22), with which latter the fan wheel is drivingly connected. Arranged on a circuit board (17) are components (11) that are coolable, at least in part, by an air flow (13) generated during operation by that fan wheel (26; 170). Associated with the fan wheel is an air-directing element (100) that is mounted on the circuit board (17) separately from the electric motor (18) so that, in operation, a cooling air flow (13) is generated which emerges from the fan arrangement (16) between the circuit board (17) and air-directing element (100).