A power tool is provided including a power supply interface having a first node and a second node, a power switch circuit, an input unit actuatable by a user, a controller configured to control the power switch circuit to regulate the supply of electric power, and a driver circuit disposed between the controller and the power switch circuit configured to receive control signals from the controller and drive the power switch circuit according. A no-volt prevention circuit is configured to enable a supply of power to at least one of the driver circuit or the controller when the input unit is actuated after the power supply interface is coupled to the power supply, but not when the input unit is actuated before to the power supply interface is coupled to the power supply.

A power tool is provided including a power supply interface having a first node and a second node, a power switch circuit, an input unit actuatable by a user, a controller configured to control the power switch circuit to regulate the supply of electric power, and a driver circuit disposed between the controller and the power switch circuit configured to receive control signals from the controller and drive the power switch circuit according. A no-volt prevention circuit is configured to enable a supply of power to at least one of the driver circuit or the controller when the input unit is actuated after the power supply interface is coupled to the power supply, but not when the input unit is actuated before to the power supply interface is coupled to the power supply.

A system comprises a stator magnetically coupled to a rotor and a plurality of conductor assemblies distributed evenly along a perimeter of the device, wherein each conductor assembly is evenly distributed into at least two branches of conductors, and wherein each branch comprising a plurality of conductors, all the branches form a plurality of windings, wherein a winding comprises a positive segment and a negative segment, and wherein each segment has a plurality of branches, and wherein one segment is in more than two conductor assemblies and the plurality of windings is symmetrically divided into a plurality of groups, wherein each group of windings forms a balanced multi-phase system and is connected to a connection bar, and wherein at least two connection bars are isolated from each other.

A power tool including a power supply interface, a motor control circuit configured to regulate supply of power from the power supply interface to a motor, and an input unit actuatable by a user. A no-volt prevention circuit receives a first voltage signal from the power supply interface and a second voltage signal from the input unit. The no-volt protection circuit includes a main semiconductor switch arranged on a current path from the power supply interface to at least one component of the motor control circuit, and a resistor-capacitor circuit to turn the main semiconductor switch ON when the input unit is actuated after the power supply interface is coupled to the power supply, but not when the input unit is actuated before to the power supply interface is coupled to the power supply.

A power tool including a power supply interface, a motor control circuit configured to regulate supply of power from the power supply interface to a motor, and an input unit actuatable by a user. A no-volt prevention circuit receives a first voltage signal from the power supply interface and a second voltage signal from the input unit. The no-volt protection circuit includes a main semiconductor switch arranged on a current path from the power supply interface to at least one component of the motor control circuit, and a resistor-capacitor circuit to turn the main semiconductor switch ON when the input unit is actuated after the power supply interface is coupled to the power supply, but not when the input unit is actuated before to the power supply interface is coupled to the power supply.

A method for controlling transient operation of a variable flux machine (VFM) includes, during a shunt angle transition, receiving a commanded and measured shunt angle when operating in a predetermined operating region, e.g., maximum torque per ampere or field weakening. The method includes calculating d-axis and q-axis delta current terms (I.sub.d and I.sub.q) required to maintain an output torque level of the VFM through a duration of the shunt angle transition, then applying the required I.sub.d and I.sub.d terms as feed-forward terms to adjust a d-axis current (I.sub.d) term and a q-axis current (I.sub.q) term from a respective lookup table. In this manner the controller maintains the output torque level of the VFM during the shunt angle transition. An electric powertrain includes the VFM, a TPIM, and the controller. A PM machine may be controlled by substituting temperature for shunt angle.

A method for controlling an electric motor including a mechanical commutator, includes determining points in time at which commutation takes place by a sensor or without a sensor. The method further includes controlling the electric motor by a supply voltage signal having a sequence of pulses. The method further includes modulating the supply voltage signal by a modulation signal to reduce the magnitude of the supply voltage signal at the commutation points in time.

A method for controlling an electric motor including a mechanical commutator, includes determining points in time at which commutation takes place by a sensor or without a sensor. The method further includes controlling the electric motor by a supply voltage signal having a sequence of pulses. The method further includes modulating the supply voltage signal by a modulation signal to reduce the magnitude of the supply voltage signal at the commutation points in time.

Torsion control device and method for an electric impact power tool are provided. The electric impact power tool includes a motor, and the torsion control device detects an actual rotational speed of the motor to make the electric impact power tool output a preset torsion value accurately. In the torsion control method, a compensating time is calculated according to a difference between the actual rotational speed value of the motor and a preset rotational speed value.

A device comprises a rotor magnetically coupled to a stator, a plurality of slots for accommodating a plurality of conductors, wherein the plurality of slots is evenly spaced, and each slot is configured to accommodate at least one conductor of the plurality of conductors, and wherein each conductor has a first end and a second end, and wherein the second end is configured to be coupled to a power converter and a plurality of connection apparatuses connected to first ends of the plurality of conductors.