32211 results about "Resonance" patented technology

This invention relates to polyolefin compositions. In particular, the invention pertains to elastic polymer compositions that can be more easily processed on cast film lines, extrusion lamination or coating lines due to improved resistance to draw resonance. The compositions of the present invention preferably comprise an elastomeric polyolefin resin and a high pressure low density type resin.

A system and method is provided for the inductive transfer of electric power between a substantially flat primary surface and a multitude of secondary devices in such a way that the power transfer is localized to the vicinities of individual device coils. The contact free power transfer does not require precise physical alignment between the primary surface and the secondary device and can allow the secondary device or devices to be placed anywhere and in arbitrary orientation with respect to the primary surface. Such power transfer is realized without the need of complex high frequency power switching network to turn the individual primary coils on or off and is completely scalable to almost arbitrary size. The local anti-resonance architecture of the primary device will block primary current from flowing when no secondary device or devices are in proximity to the local RF power network. The presence of a tuned secondary device detunes the local anti-resonance on the primary surface; thereby enable the RF power to be transferred from the local primary coils to the secondary device. The uniformity of the inductive coupling between the active primary surface and the secondary devices is improved with a novel multi-pole driving technique which produces an apparent traveling wave pattern across the primary surface.

A ballast circuit is disclosed for inductively providing power to a load. The ballast circuit includes an oscillator, a driver, a switching circuit, a resonant tank circuit and a current sensing circuit. The current sensing circuit provides a current feedback signal to the oscillator that is representative of the current in the resonant tank circuit. The current feedback signal drives the frequency of the ballast circuit causing the ballast circuit to seek resonance. The ballast circuit preferably includes a current limit circuit that is inductively coupled to the resonant tank circuit. The current limit circuit disables the ballast circuit when the current in the ballast circuit exceeds a predetermined threshold or falls outside a predetermined range.

A lamp assembly configured to inductively receive power from a primary coil. The inductively powered lamp assembly includes a lamp circuit including a secondary and a lamp connected in series. In a first aspect, the lamp circuit includes a capacitor connected in series with the lamp and the secondary to tune the circuit to resonance. The capacitor is preferably selected to have a reactance that is substantially equal to or slightly less than the reactance of the secondary and the impedance of the lamp. In a second aspect, the inductively powered lamp assembly includes a sealed transparent sleeve that entirely encloses the lamp circuit so that the transparent sleeve is fully closed and unpenetrated. The transparent sleeve is preferably the lamp sleeve itself, with the secondary, capacitor and any desired starter mechanism disposed within its interior.

A determination is made whether a moving speed of a slider section with respect to a rod section in a piezoelectric actuator is lower than a predetermined speed. When the moving speed is lower than the predetermined speed, it is considered that a friction-bonded portion between the rod section and the slider section is in a fastened state or a nearly fastened state. A resonance frequency of the piezoelectric actuator or a frequency proximity to the resonance frequency is set as a driving frequency for the piezoelectric actuator. The slider section is moved in a reciprocating manner plural times with respect to the rod section. As a result, an abnormal state is eliminated from the piezoelectric actuator.

A switching power converter and method of controlling an output voltage thereof using predictive sensing of magnetic flux provides a low-cost switching power converter via primary-side control using a primary-side winding. An integrator generates a voltage that represents flux within a magnetic element by integrating a primary-side winding voltage. A detection circuit detects the end of a half-cycle of post-conduction resonance that occurs in the power magnetic element subsequent to zero energy level in the power magnetic element. The integrator voltage is stored at the end of the half-cycle and is used to determine a sampling point prior to or equal to the start of post-conduction resonance in a subsequent switching cycle of the power converter. The primary-side winding voltage is then sampled at the sampling point, providing an indication of the output voltage of the power converter by which the output voltage of the converter can be controlled.

An ultrasonic surgical apparatus and method, the apparatus including a signal generator outputting a drive signal having a frequency, an oscillating structure, receiving the drive signal and oscillating at the frequency of the drive signal, and a bridge circuit, detecting the mechanical motion of the oscillating structure and outputting a signal representative of the mechanical motion. The ultrasonic surgical apparatus also includes a microcontroller receiving the signal output by the bridge circuit, the microcontroller determining an instantaneous frequency at which the oscillating structure is oscillating based on the received signal, and determining a frequency adjustment necessary to maintain the oscillating structure oscillating at its resonance frequency, the microcontroller further determining the quality (Q value) of the signal received from the bridge circuit and determining material type contacting the oscillating structure.