Abstract: Handheld power tools with kickback detection and methods of detecting a kickback condition of a handheld power tool are disclosed herein. The methods include moving an implement of the handheld power tool within an implement motion plane and in detecting motion of the handheld power tool. The methods also include determining that the kickback condition exists based, at least in part, on the motion of the handheld power tool. In some embodiments, the handheld power tool is a circular saw that includes a user-actuated assembly. The user-actuated assembly includes a motion sensor, a controller, and a motor. The circular saw also includes a workpiece support and a pivot. The motion sensor is configured to detect acceleration along an acceleration detection axis that extends a threshold pivot axis-acceleration axis distance of at most 4 cm from a pivot axis of the pivot.

Abstract: The present disclosure relates to a fan motor control device comprising a control signal input for applying a rotational speed control voltage as the control signal input signal and a control signal output for picking off a control signal output signal for connecting to a fan motor, where modulation means are connected downstream from the control signal input, said modulation means being designed to convert the control signal input signal into a digital and/or pulsed modulation input signal, and isolated transmission means are connected downstream therefrom, which transfer the digital and/or pulsed modulation input signal into a digital and/or pulsed modulation output signal isolated from the control signal input, which is converted into the control signal output signal that can be picked off on the control signal output by means of demodulation means connected downstream from the transmission means.

Abstract: The present disclosure relates to a fan motor control device comprising a control signal input for applying a rotational speed control voltage as the control signal input signal and a control signal output for picking off a control signal output signal for connecting to a fan motor, where modulation means are connected downstream from the control signal input, said modulation means being designed to convert the control signal input signal into a digital and/or pulsed modulation input signal, and isolated transmission means are connected downstream therefrom, which transfer the digital and/or pulsed modulation input signal into a digital and/or pulsed modulation output signal isolated from the control signal input, which is converted into the control signal output signal that can be picked off on the control signal output by means of demodulation means connected downstream from the transmission means.

Abstract: An electric fan has a drive motor having a fan rotor, an apparatus for generating a rotation speed signal (n_i), an apparatus for generating a power level signal (P_i) that represents power consumed; a first regulator (n_RGL) for regulating the rotation speed signal (n_i) to a predefined target value (n_s); a second regulator (P_RGL) for regulating the power level signal (P_i) to a predefined power level signal target value (P_s) that corresponds to a predefined minimum consumed power level (P_min), where the first regulator (n_RGL) and the second regulator (P_RGL) apply at least one control output signal (SW) to the drive motor and interact in such a way that, during operation, the at least one control value (SW) in a first state is determined by the first regulator (n_RGL), and in a second state is determined by the second regulator (n_RGL).

Abstract: A mixed-flow fan features a housing (42); an impeller (43) journaled rotatably with respect to the housing, and equipped with fan blades (54); a generally cylindrical air conduit (50) defined between the fan housing and the impeller, the fan blades extending into the air conduit in order, during operation, to transport air; an external-rotor motor (75) having an internal stator (100) and an external rotor (81) which includes a tubular ferromagnetic yoke (63) partly embedded in material of the impeller. A cup-shaped yoke (72) fits into a central cavity (68) of the tubular yoke (63) and accommodates a permanent magnet arrangement (66) which interacts with the stator. The tubular yoke (63) and the cup-shaped yoke (72) together serve as a magnetic return path for the external-rotor motor. The structure minimizes damage during final assembly, and simplifies insertion of balancing weights.

Abstract: Embodiments relate to systems and methods for reducing jitter caused by frequency modulation of a clock signal including modulating the frequency of the clock signal based on a predetermined modulation signal m(t), and compensating an accumulated jitter J(t) caused by the frequency modulation of the clock signal such that an absolute value of the accumulated jitter J(t) never exceeds a predetermined jitter limit Jlim.

Abstract: An electric fan has a drive motor having a fan rotor, an apparatus for generating a rotation speed signal (n_i), an apparatus for generating a power level signal (P_i) that represents power consumed; a first regulator (n_RGL) for regulating the rotation speed signal (n_i) to a predefined target value (n_s); a second regulator (P_RGL) for regulating the power level signal (P_i) to a predefined power level signal target value (P_s) that corresponds to a predefined minimum consumed power level (P_min), where the first regulator (n_RGL) and the second regulator (P_RGL) apply at least one control output signal (SW) to the drive motor and interact in such a way that, during operation, the at least one control value (SW) in a first state is determined by the first regulator (n_RGL), and in a second state is determined by the second regulator (n_RGL).

Abstract: A diagonal ventilating fan (30) has a fan housing (36) and a fan wheel (80), rotatable around a rotation axis, that has associated with it an electric motor (73) to drive it, the fan wheel (80) extending in the direction of the rotation axis between an air inlet side and an air outlet side of the diagonal ventilating fan (30) and serving, as it rotates, to convey air in a main delivery direction from the air inlet side to the air outlet side. The fan wheel (80) has a preferred rotation direction so that, during operation, its blades (82) each have a front side and a back side, and a negative-pressure zone (110) occurs, during operation, adjacent each respective back side of a blade (82). An auxiliary cooling air blower (76) connects to the respective zones (110) to provide an improved flow of cooling air for the electric motor (73).

Abstract: Embodiments relate to systems and methods for reducing jitter caused by frequency modulation of a clock signal including modulating the frequency of the clock signal based on a predetermined modulation signal m(t), and compensating an accumulated jitter J(t) caused by the frequency modulation of the clock signal such that an absolute value of the accumulated jitter J(t) never exceeds a predetermined jitter limit Jlim.

Abstract: A mixed-flow fan features a housing (42); an impeller (43) journaled rotatably with respect to the housing, and equipped with fan blades (54); a generally cylindrical air conduit (50) defined between the fan housing and the impeller, the fan blades extending into the air conduit in order, during operation, to transport air; an external-rotor motor (75) having an internal stator (100) and an external rotor (74) which includes a tubular ferromagnetic yoke (63) partly embedded in material of the impeller. A cup-shaped yoke (72) fits into a central cavity (68) of the tubular yoke (63) and accommodates a permanent magnet arrangement (66) which interacts with the stator. The tubular yoke (63) and the cup-shaped yoke (72) together serve as a magnetic return path for the external-rotor motor. The structure minimizes damage during final assembly, and simplifies insertion of balancing weights.

Abstract: An electronically commutated asynchronous motor (12) features a stator (202), a short-circuit rotor (204), a controller (FOR 20) for field-oriented regulation of the motor (12), a sensor magnet (274) in thermally conductive connection with the short-circuit rotor (204), a rotor position sensor (14A; 18; 18?) arranged at a predetermined distance (d) from the sensor magnet (274) to generate an output signal (HALL, U, U1, U2) that is dependent upon the spatial orientation of the sensor magnet (274), and a temperature evaluation apparatus (CALC_T 44) configured to ascertain, during operation, from the sensor output signal (HALL, U, U1, U2), a temperature value (T) that characterizes a temperature (T_SM, T_S) in the motor (12).

Abstract: A seat for a bicycle has a seat body and a seat post. The seat body a front end, a rear end, a bottom and multiple reinforced ribs. The rear end has a width larger than that of the front end. The reinforced ribs are formed on the bottom of the seat body. The seat post is integrally formed on and protrudes from the bottom of the seat body. With the seat post being integrally formed on the seat body, the manufacturing process for the seat is simplified and the cost therefor is accordingly lowered.

Abstract: A circuit board (20) is equipped with at least one conductor path (22) and a contact element (44). The latter is adapted to mechanically engage and electrically contact an electrical conductor (66). In the region of a conductor path (22), the circuit board (20) has passthrough orifices (24, 26, 28, 30, 32). The contact element (44) has a base part (46) and feet (34, 36, 38, 40, 42) which press-fit into the orifices (24 to 32) of the circuit board (20). The contact element (44) has a contact tongue (54) that is resiliently articulated on the base part (46) and clamps the electrical conductor (66). This makes possible a secure connection from the electrical conductor (66) to the circuit board (20), e.g. for connecting a device having a large current demand.

Abstract: An electronically commutated asynchronous motor (12) features a stator (202), a short-circuit rotor (204), a controller (FOR 20) for field-oriented regulation of the motor (12), a sensor magnet (274) in thermally conductive connection with the short-circuit rotor (204), a rotor position sensor (14A; 18; 18?) arranged at a predetermined distance (d) from the sensor magnet (274) to generate an output signal (HALL, U, U1, U2) that is dependent upon the spatial orientation of the sensor magnet (274), and a temperature evaluation apparatus (CALC_T 44) configured to ascertain, during operation, from the sensor output signal (HALL, U, U1, U2), a temperature value (T) that characterizes a temperature (T_SM, T_S) in the motor (12).

Abstract: A circuit board (20) is equipped with at least one conductor path (22) and a contact element (44). The latter is adapted to mechanically engage and electrically contact an electrical conductor (66). In the region of a conductor path (22), the circuit board (20) has passthrough orifices (24, 26, 28, 30, 32). The contact element (44) has a base part (46) and feet (34, 36, 38, 40, 42) which press-fit into the orifices (24 to 32) of the circuit board (20). The contact element (44) has a contact tongue (54) that is resiliently articulated on the base part (46) and clamps the electrical conductor (66). This makes possible a secure connection from the electrical conductor (66) to the circuit board (20), e.g. for connecting a device having a large current demand.

Abstract: An electronically commutated motor comprises a rotor (208); a stator (201) electromagnetically interacting with the rotor (208), which stator is formed with a stator winding (202, 204, 206); a power stage (122) controlling the currents flowing in the stator winding (202, 204, 206) during operation; at least one current measuring element (242, 244) for sensing a measured value for the currents (I_UPPER, I_LOWER) flowing in the power stage, and an overcurrent measuring element (152, 162) for evaluating an associated measured value and for sensing a current whose absolute value exceeds a predetermined limit value (I_MAX_UPPER, I_MAX_LOWER); a holding element (154, 164) associated with the overcurrent measuring element (152, 162), configured, when an overcurrent occurs in the associated current measuring element (242, 244), to generate an overcurrent signal (OC_UPPER, OC_LOWER), to store the signal, and to deliver a signal to the power stage (122).

Abstract: A method for correcting errors in a coordinate measuring machine having a measuring head which is adapted to move in at least two different spatial directions. Measuring scales and measuring lines are assigned to each spatial direction. The measuring lines of different spatial directions intersect, and correction values are determined along the measuring lines at predetermined values of the scales in order to correct for elastic and/or geometric errors of the scales and/or of the guiding mechanism for moving the measuring head. According to one aspect of the invention, the correction values determined along a measuring line of a first spatial direction are modified such that the modified correction value of this measuring line assumes a predetermined value at the point of intersection with a first measuring line of a second spatial direction.

Abstract: An electronically commutated motor (10) is adapted to be powered directly by an AC voltage (UAC) source, and comprises a permanent-magnet rotor (18), a stator having at least one winding phase (L1, L2, . . . , Ln), a rectifier (38) which generates, from the AC voltage (UAC), a pulsating DC voltage (UB) between a positive lead (30) and a negative lead (32) of a DC link (15). Also present is a bridge circuit (28A, 28B, 28C), connected to that DC link (15) and provided to supply current to the at least one winding phase (L1, L2, . . . , Ln), which comprises a switching element (50) controllable with a control voltage (UST) that is lower than the pulsating DC voltage (UB) to be switched. An auxiliary circuit (34, 34?) generates, from the pulsating DC voltage (UB) at the DC link and from the AC voltage (UAC), a control voltage (UST) for driving the switching element (50) that is lower than the pulsating DC voltage by an amount equal to a predetermined value (U?).

Abstract: A method for correcting errors in a coordinate measuring machine having a measuring head which is adapted to move in at least two different spatial directions. Measuring scales and measuring lines are assigned to each spatial direction. The measuring lines of different spatial directions intersect, and correction values are determined along the measuring lines at predetermined values of the scales in order to correct for elastic and/or geometric errors of the scales and/or of the guiding mechanism for moving the measuring head. According to one aspect of the invention, the correction values determined along a measuring line of a first spatial direction are modified such that the modified correction value of this measuring line assumes a predetermined value at the point of intersection with a first measuring line of a second spatial direction.