Abstract: A fan (20) has: a motor having a stator (40) and having a rotor (60) with at least one fan blade; at least one air inlet having an air entrance opening (102) for the inlet of air; at least one air outlet having an air exit opening (32) for the outlet of air; a circuit board (80) having at least one recess, which circuit board (80) is arranged in the region of the air inlet in such a way that air can enter the fan (20) through the recess, motor electronics (88) being arranged on the circuit board (80). In a preferred embodiment, a Negative Temperature Coefficient (NTC) resistor (84) is surface-mounted on a PC board portion (83) extending into the air passage, to thereby sense air temperature. This facilitates compact, automated construction.

Abstract: A fan has a sensor (86; 186) for sensing at least one value of the air that flows through the fan (20; 120). The fan has a fan housing (22, 24; 122, 124); an electronically commutated external-rotor motor, arranged in that housing, having an internal stator (30; 130) and an external rotor (46; 146); a fan wheel (56; 156) coupled to the external rotor (46; 146); an air inlet opening (58; 90; 158) for the inflow of air that is to be moved by the fan wheel (56; 156); a circuit board (68; 185) having a portion (66; 188) that extends adjacent the air passage opening (58; 158); and conductors (82, 84; 182?, 182?) arranged on that portion (66; 188), to which conductors the sensor (86; 186) is connected, preferably by a Surface Mounted Device (SMD) method. Premounting the sensor on the circuit board facilitates automated manufacture and reduces cost.

Abstract: A fan (100) has an electronically commutated drive motor (ECM 52) with a stator (50) connected to a bearing tube (54) and a rotor (22) on a shaft (34). The shaft (34) is journaled in the tube (54) using passive radial magnetic bearings (16, 18) to minimize friction and wear, is axially displaceable with respect to the tube (54), and is drivingly connected to a rotor magnet (44) forming a first magnetic yoke (46). A second magnetic yoke (27) is connected to the shaft (34), and has an inner surface (59) defining a substantially cylindrical air gap (57) through which, during operation, a radial magnetic flux (55?) extends. A plunger coil (64) extends into the air gap (57) and is mechanically connected to the tube (54) so that, upon axial displacement of the plunger coil (64), the position of the shaft (34) with respect to the tube (54) changes.

Abstract: An electronically commutated motor (ECM 21) has reduced vulnerability to Electro-Static Discharge (ESD). The motor has an internal stator (50) and an external rotor (22) equipped with a permanent magnet (28), which rotor is separated by an air gap from the internal stator (50). The rotor has a shaft (34) on which a magnetic yoke element (24) is mounted. A leakage flux region on an end face (27) of the magnet (28) actuates a Hall sensor (48) located adjacent a first aperture (48?) in a circuit board (46) supporting electronic control components. In order to prevent static discharges from passing through the first aperture (48?) and endangering the electronic components, the circuit board (46) is formed with a second aperture (43) on whose edge is provided at least one electrical conductor (95?, 95?), connected to ground (112), to which any charge that builds up during operation can harmlessly discharge.

Abstract: An equipment fan has a housing (22) that externally defines an air passage opening (41) provided in the fan (20). The fan has a motor (21) for rotatably driving blades (40) about a rotation axis (23), as well as a carrier element (51), provided between the motor (21) and the housing (22), which extends transversely to the passage (41) and is configured as a trough (53) that serves to receive an electrical lead (52) and guides the lead along a predetermined path from the motor (21) to a location (64) on the housing (22). The fan also has a deflection device (50) which, by deflecting the lead (52) at a first deflection location (55) and at a second deflection location (84) and in at least two planes extending at a predetermined angle with respect to one another, effects strain relief for the lead (52) that proceeds to the motor (21).

Abstract: A control circuit (150) for controlling the current supplied to a winding strand (102) in an electric motor (143). The control circuit comprises at least one semiconductor switch (106) and a control unit (108) for controlling the semiconductor switch(es). Each semiconductor switch (106) is connected to a respective winding strand (102), in order to control the current in said winding strand. The control unit (108) comprises an output (110) for applying a control signal (CTRL) to the semiconductor switch (106), and is configured to set the output (110), at least upon switch-off of the semiconductor switch (106), to high impedance in order to prevent a voltage at the control unit output from influencing, during the switch-off operation, a signal input at the semiconductor switch (106). The improved control circuit increases motor efficiency and reduces commutation noise.