An electrical system including a linear motor in which energized forcer and thruster coils are used for the field and armature elements, respectively. In accordance with various exemplary embodiments, one or more thruster coils may be provided on a reciprocating shaft with opposing single or multiple fixed forcer coils. Using coils as the electromagnets for both forcer and thruster coils advantageously provides necessary power while also minimizing system weight and decreases in magnetism typically encountered with permanent magnets with rising temperature, resulting in higher and more controllable magnetic forces over varying temperatures. A ferrous system housing and open ferrous containers for the thruster coils may be further included to advantageously focus the magnetic forces. Additionally, multiple forcer and thruster coils may be disposed in various arrangements along the reciprocating shaft. Exemplary applications include use of such a system for controlling oscillations of a poppet valve in an internal combustion engine.

An electrical system including a linear motor in which energized forcer and thruster coils are used for the field and armature elements, respectively. In accordance with various exemplary embodiments, one or more thruster coils may be provided on a reciprocating shaft with opposing single or multiple fixed forcer coils. Using coils as the electromagnets for both forcer and thruster coils advantageously provides necessary power while also minimizing system weight and decreases in magnetism typically encountered with permanent magnets with rising temperature, resulting in higher and more controllable magnetic forces over varying temperatures. A ferrous system housing and open ferrous containers for the thruster coils may be further included to advantageously focus the magnetic forces. Additionally, multiple forcer and thruster coils may be disposed in various arrangements along the reciprocating shaft. Exemplary applications include use of such a system for controlling oscillations of a poppet valve in an internal combustion engine.

An electric DC motor system for a cordless powered device includes a rotor and a stator having a plurality of non-curved permanent magnets. Each of the magnets includes six substantially flat and rectangular faces. The cordless powered device may be a vacuum cleaner, power tool, garden tool, lawn tool or the like.

An electric DC motor system for a cordless powered device includes a rotor and a stator having a plurality of non-curved permanent magnets. Each of the magnets includes six substantially flat and rectangular faces. The cordless powered device may be a vacuum cleaner, power tool, garden tool, lawn tool or the like.

The method for controlling a rotating electric machine according to the invention comprises a step of controlling the phase currents of the machine by means of a full-wave control (C). According to the invention, the full-wave control (C) is generated via a pulse width modulated signal of which the signal frequency is greater than an electric frequency of the machine. According to another feature, ascending or descending fronts (24, 25) of the pulse width modulated signal are synchronised with first and second crossings of first and second angular switching thresholds (S1, S2) by an electric position () of the machine and a duty ratio () of the pulse width modulated signal is periodically refreshed to the signal frequency.

A method of operating a resolver management device according to the present invention includes: generating an excitation signal by using an external control signal; counting a time interval (a first delay time) to a first pole of the excitation signal based on one period of the external control signal by using an internal clock; receiving an excitation signal reflected from a resolver sensor; counting a time interval (a second delay time) to a second pole of the reflected excitation signal at the first pole by using the internal clock; and transmitting a first count value corresponding to the first delay time and a second count value corresponding to the second delay time to a microcontroller unit (MCU).

Gate driver circuit for driving power transistor includes: gate line to be connected to the transistor; source line to be connected to the transistor; first current source sourcing current to the gate line; and second current source sinking current from the gate line, wherein the first current source includes: first reference impedance element connected to power supply line; first reference transistor installed between the first reference impedance element and the gate line; first error amplifier having output connected to gate of the first reference transistor, one input connected to the first reference impedance element, and the other input where first reference voltage is input; and first transistor elements installed between the power supply line and the gate line, and wherein the first current source is switched between a state, in which gate of each first transistor element is connected to the output of the first error amplifier, and OFF state.

In a surgical power tool that includes an electric motor positioned in a housing and a movable element extending from the housing and operatively actuated by the electric motor, a controller can repeatedly interrogate for faults a plurality of components in or on the housing, such as the electric motor, the controller, a battery, a trigger, and a mode switch. Upon finding a component in a fault condition, the controller can engage a critical error handler that disengages the electric motor, disables at least some of the plurality of components, and directs a microprocessor in the controller into a safe software state. Upon engaging the critical error handler, the controller can further write to a memory an error code corresponding to which of the plurality of components is in the fault condition. The error code can be accessible via a wired or wireless connection.

To select the configuration of a linear motor more appropriately. A motor configuration selection device according to the present invention comprises a characteristic calculation unit that calculates at least one of force and magnetic attraction to be achieved by a component of a linear motor based on a gap between a field magnet and an armature in the linear motor to be selected.

To select the configuration of a linear motor more appropriately. A motor configuration selection device according to the present invention comprises a characteristic calculation unit that calculates at least one of force and magnetic attraction to be achieved by a component of a linear motor based on a gap between a field magnet and an armature in the linear motor to be selected.