A double-fed oscillating linear alternator is provided that includes two concentric Halbach type arrays, one stationary and one movable, that do not require magnets or iron laminations to create a strong magnetic field between the two arrays where the movable array oscillates in a linear motion with respect to the stationary array. The two arrays are manufactured from magnet-less and iron-less conductive material using additive manufacturing techniques.

A double-fed oscillating linear alternator is provided that includes two concentric Halbach type arrays, one stationary and one movable, that do not require magnets or iron laminations to create a strong magnetic field between the two arrays where the movable array oscillates in a linear motion with respect to the stationary array. The two arrays are manufactured from magnet-less and iron-less conductive material using additive manufacturing techniques.

Embodiments described herein may take the form of an electromagnetic actuator that produces a haptic output during operation. Generally, an electromagnetic coil is wrapped around a central magnet array. A shaft passes through the central magnet array, such that the central array may move along the shaft when the proper force is applied. When a current passes through the electromagnetic coil, the coil generates a magnetic field. The coil is stationary with respect to a housing of the actuator, while the central magnet array may move along the shaft within the housing. Thus, excitation of the coil exerts a force on the central magnet array, which moves in response to that force. The direction of the current through the coil determines the direction of the magnetic field and thus the motion of the central magnet array.

Embodiments described herein may take the form of an electromagnetic actuator that produces a haptic output during operation. Generally, an electromagnetic coil is wrapped around a central magnet array. A shaft passes through the central magnet array, such that the central array may move along the shaft when the proper force is applied. When a current passes through the electromagnetic coil, the coil generates a magnetic field. The coil is stationary with respect to a housing of the actuator, while the central magnet array may move along the shaft within the housing. Thus, excitation of the coil exerts a force on the central magnet array, which moves in response to that force. The direction of the current through the coil determines the direction of the magnetic field and thus the motion of the central magnet array.

Provided is a linear vibration motor, including: a housing having a receiving space; a vibration unit received in the receiving space; an elastic assembly configured to suspend the vibration unit in the receiving space, and a driving unit fixed to the housing and configured to drive the vibration unit to vibrate. The linear vibration motor includes a coil assembly and two first permanent magnets respectively provided at two sides of the coil assembly. The vibration unit includes one of the coil assembly and the first permanent magnets, and the driving unit includes the other one. When the vibration unit is static, a central axis of the first permanent magnet perpendicular to a vibrating direction of the vibration unit and a central axis of the coil assembly perpendicular to the vibrating direction of the vibration unit are spaced apart from each other in the vibrating direction of the vibration unit.

An electronic watch comprising a timekeeper logic unit (42) set to control a display (50,54) of the time, and a controller (48), in communication with an external device (90) or with Internet (99) through a wireless interface (68) of the watch, and a mechanical energy harvester system (25) set to transform mechanical energy deriving from the movements of a wearer to electrical energy, a power manager circuit for storing the electrical energy in a battery (30) and/or in a capacitor (32), and to supply the logic unit (42), the controller (48) and the wireless interface (68) with energy stored in the battery (30) and/or in the capacitor (32).

The invention relates to a device (100) for detecting the falling of a door leaf (2) of a door (1), preferably a high-speed industrial door (1), the device (100) for detecting the falling of a door leaf being provided on or in the door leaf (2). The device (100) for detecting the falling of a door leaf comprises a means for detecting the acceleration of said device (100) in at least one falling direction of the device (100), and a wireless communication unit (200) for emitting a falling warning signal in the event of a falling of the door leaf (2) being positively detected. The positive detection of the falling of the door leaf (2) is based on an acceleration being detected in the falling direction.

The operating unit for a vehicle is provided with a housing and an operating element elastically mounted in and/or on the housing, wherein the elastically mounted operating element forms a spring-mass system having a construction-related resonance frequency. The operating unit is further provided with an actuator for pulse-shaped mechanical excitation of the operating element, and a control unit for controlling the actuator when manually actuating the operating element. The resonance frequency is, due to construction, above the highest cut-off frequency that can typically still be detected by receptors for haptic feedback and/or for tactile sensation of a person. The frequency spectrum of the mechanical pulse at the resonance frequency and/or at one of the harmonics of the resonance frequency has no frequency components in that the power density spectrum above the cut-off frequency is energy-free or substantially energy-free.

The operating unit for a vehicle is provided with a housing and an operating element elastically mounted in and/or on the housing, wherein the elastically mounted operating element forms a spring-mass system having a construction-related resonance frequency. The operating unit is further provided with an actuator for pulse-shaped mechanical excitation of the operating element, and a control unit for controlling the actuator when manually actuating the operating element. The resonance frequency is, due to construction, above the highest cut-off frequency that can typically still be detected by receptors for haptic feedback and/or for tactile sensation of a person. The frequency spectrum of the mechanical pulse at the resonance frequency and/or at one of the harmonics of the resonance frequency has no frequency components in that the power density spectrum above the cut-off frequency is energy-free or substantially energy-free.

A condition monitoring system for monitoring a rolling element bearing. The system includes a signal processing unit and a vibration energy harvester. The vibration energy harvester provides an electromagnetic transducer. When vibrated, a coil moves relative to a static electromagnetic field to create power. To create a compact and efficient condition monitoring system, it uses the electromagnetic transducer also as a vibration sensor, a velocity sensor. The signal processing unit determines if the bearing has been damaged and in some embodiments also the extent of the damage. The electromagnetic transducer is attached directly or indirectly to the rolling element bearing.