Abstract: A linear actuator includes a moving part which has a facing surface and which is provided such that the facing surface of the moving part faces a facing surface of a stator. The moving part is lonearly movable. A permanent magnet is provided in one of the stator or the moving part and has a magnet surface facing the facing surface of another of the stator or the moving part. A cross-sectional area of the permanent magnet along a first plane substantially in parallel with the facing surface of the one of the stator or the moving part reduces toward the magnet surface.

Abstract: A magnetic impact device includes at least one hammer relatively movable with respect to at least one chuck. One of the at least one hammer and the at least one chuck has at least one magnet. Another of the at least one hammer and the at least one chuck has at least one magnet or magnetic material. A driving unit is configured to move the at least one hammer relatively to the at least one chuck to magnetically generate impact motion of the at least one chuck.

Abstract: A magnetic impact device includes at least one hammer relatively movable with respect to at least one chuck. One of the at least one hammer and the at least one chuck has at least one magnet. Another of the at least one hammer and the at least one chuck has at least one magnet or magnetic material. A driving unit is configured to move the at least one hammer relatively to the at least one chuck to magnetically generate impact motion of the at least one chuck.

Abstract: A dual sided self-oscillation circuit for driving an oscillatory actuator with high efficiency and high response speed. The actuator has a winding to receive a periodical supply current from a power source and oscillates in a predetermined resonant frequency. The self-oscillation circuit includes a bandpass filter for receiving a back electromotive force voltage (Vbemf) developed across the winding and producing a sine wave output signal, a comparator for comparing the sine wave output signal with a threshold voltage and producing two drive pulses per cycle of the resonant frequency, and a switch connected in series with the winding to connect or disconnect the power source to the winding in response to the drive pulses, thereby flowing electric current in two directions at each cycle.

Abstract: An improved self-oscillation system for a linear oscillatory actuator composed of a stator and a reciprocator. The stator carries a winding to which an electric current is periodically supplied for making a resonant oscillation of the reciprocator. The system includes a self-oscillation circuit for continuing the resonant oscillation of the actuator by a positive feedback manner based upon a back electromotive force (Vbemf) appearing across the winding. The system further includes a PWM control for increasing the electric current in response to a decreasing oscillation amplitude due to an increasing load applied to the reciprocator. A detector circuit is included to monitor the oscillation amplitude of the reciprocator and provides a corresponding detector output in response to which the self-oscillation circuit provides a drive pulse of varying pulse width for making the PWM control.

Abstract: A dual sided self-oscillation circuit for driving an oscillatory actuator with high efficiency and high response speed. The actuator has a winding to receive a periodical supply current from a power source and oscillates in a predetermined resonant frequency. The self-oscillation circuit includes a bandpass filter for receiving a back electromotive force voltage (Vbemf) developed across the winding and producing a sine wave output signal, a comparator for comparing the sine wave output signal with a threshold voltage and producing two drive pulses per cycle of the resonant frequency, and a switch connected in series with the winding to connect or disconnect the power source to the winding in response to the drive pulses, thereby flowing electric current in two directions at each cycle.

Abstract: An improved self-oscillation system for a linear oscillatory actuator composed of a stator and a reciprocator. The stator carries a winding to which an electric current is periodically supplied for making a resonant oscillation of the reciprocator. The system includes a self-oscillation circuit for continuing the resonant oscillation of the actuator by a positive feedback manner based upon a back electromotive force (Vbemf) appearing across the winding. The system further includes a PWM control for increasing the electric current in response to a decreasing oscillation amplitude due to an increasing load applied to the reciprocator. A detector circuit is included to monitor the oscillation amplitude of the reciprocator and provides a corresponding detector output in response to which the self-oscillation circuit provides a drive pulse of varying pulse width for making the PWM control.

Abstract: The method of power transmission and distribution aims to mitigate the magnetic fields generated at a right of way and at distances which extend beyond the right of way. The transmission and distribution lines use various line parameters including the relative locations of the conductors around the axis of symmetry of the right of way, the current magnitudes and the phase angles of the currents flowing in the conductors in optimum asymmetric fashion. The use of magnetic field mitigation bodies placed adjacent to the current bearing conductors increases the scope and the effectiveness of the mitigation. A mitigation technique is also provided for mitigating the magnetic field generated by current bearing sources used in power distribution, with unknown or difficult to characterize current distributions, such as transformers.

Abstract: A method and apparatus for mitigation of magnetic fields from magnetic field sources operating at low frequencies, typically less than 100 KHZ, are provided. The method is based on placing magnetic bodies of proper shape, size and physical properties close to the source of the magnetic field to cancel or reduce the magnetic field at desired sites, located away from the source. The method is applicable to mitigating all sources of magnetic fields including those generated by electric power lines, transformers, various tools, electronic devices and appliances. The apparatus, an application of the method to electric power transmission lines, consists of body of magnetic material disposed adjacent to at least one conductor of a multi-line electric power transmission system.

Abstract: An improved rheometer of the present invention includes an adjustable gap through which a flowing system is forced. The inner cavity dimension of the gap is variable so as to give a user of the rheometer an ability to vary the separation gap and the length over diameter ratio. This, in turn, allows the user to determine the shear rate and shear stress along the wall of the cavity for varying deformation rates. Thus, the shear viscosity of the flowing system can be characterized for non-Newtonian systems without varying the volumetric flow rate. One of the preferred embodiments of the adjustable gap rheometer is a slit rheometer in which the flowing system is forced through a slit having generally more length than width and more width than gap. The slit rheometer is made adjustable by holding the body of the rheometer stationary while moving an adjustable wall which forms one of the sides of the slit.