Abstract: A network security system for wireless devices derives a fingerprint from the modulation imperfections of the analog circuitry of the wireless transceivers. These fingerprints may be compared to templates obtained when the wireless devices are initially commissioned in a secure setting and used to augment passwords or other security tools in detecting intruders on the network.

Abstract: An inductive element for transforming and/or regulating voltage input from a multi-phase, interleaved power supply system into an output voltage to a load is disclosed. The multi-phase, interleaved power supply system includes a plurality of pulsed power sources, each of which is adapted to provide voltage at a discrete phase. The inductive element includes a magnetic core having, for each power supply, a distinct area of relatively-high magnetic reluctance, which is surrounded by areas of relatively-low magnetic reluctance, and a pair of windings. Each of the pair of windings includes a first, phase winding that is electrically coupled to an output of one of the pulsed power source and to the load, and a second, loop winding that is operatively coupled and proximate to the first, phase winding. Each of the second, loop windings is disposed serially on a closed loop.

Abstract: The present invention provides an improved method of performing bone resection, including during arthroplasty procedures, wherein a laser guide is utilized to align cutting blocks and/or measuring devices. The present invention also provides laser guidance platforms for use in the methods of the invention.

Abstract: An inductive element for transforming and/or regulating voltage input from a multi-phase, interleaved power supply system into an output voltage to a load is disclosed. The multi-phase, interleaved power supply system includes a plurality of pulsed power sources, each of which is adapted to provide voltage at a discrete phase. The inductive element includes a magnetic core having, for each power supply, a distinct area of relatively-high magnetic reluctance, which is surrounded by areas of relatively-low magnetic reluctance, and a pair of windings. Each of the pair of windings includes a first, phase winding that is electrically coupled to an output of one of the pulsed power source and to the load, and a second, loop winding that is operatively coupled and proximate to the first, phase winding. Each of the second, loop windings is disposed serially on a closed loop.

Abstract: An evaluator (210) having an input (207) for receiving a signal indicative of a channel current sensed via a sensor in a mutlichannel current sharing system, and circuitry (313, 319) coupled to the input (207) and responsive to the signal for indicating an unreliable sensing for the sensor when a low current condition occurs for a time period exceeding the switching time period of the channel current. Further, the apparatus can include an additional input (207) and circuitry (313, 319) for evaluating an additional sensor sensing an additional channel current. The low current condition is characterized by thresholds corresponding to the peak level and a valley level of the channel current over a switching time period.

Abstract: A pulse width modulator (305) for driving a load in a multi-phased power system having circuitry (270) responsive to channel signals for providing an average signal by summing the channel signals at a node (221) which is coupled with a plurality of resistive elements, and having further circuitry for providing an error between said load and said reference potential, and having still further circuitry (250) for summing the channel signals, average signal, and error for providing a respective drive signal for each of the power switches, wherein the error signal and the average signal have complementary effects on a duty factor of the drive signals and the channel signal has an effect contrary to the error signal and the average signal. Further, a plurality of pulse width modulators (305) can be combined as a system (300) by connecting respective nodes (221) for providing current sharing between all phases.

Abstract: A highly efficient multi-phase power system having both reduced size and reduced cost. The multi-phase power system includes a plurality of Pulse Width Modulation (PWM) controllers. A first controller is programmed to function as a “master” controller, and the remaining controller(s) are programmed to function as “slave” controllers. Each controller includes a synchronous counter and control logic circuitry. The control logic generates at least one synchronization output signal based on the outputs of the counter and the programming state (i.e., master or slave) of the controller. The master controller generates a master clock signal having a synchronizing state encoded thereon and provides the master clock to the slave controller, which includes synchronization circuitry for receiving the master clock and resetting the counter based on the synchronizing state of the master clock, thereby assuring that appropriate phase relationships are maintained between the controller outputs.

Abstract: A highly efficient multi-phase power system having both reduced size and reduced cost. The multi-phase power system includes a plurality of Pulse Width Modulation (PWM) controllers. A first controller is programmed to function as a “master” controller, and the remaining controller(s) are programmed to function as “slave” controllers. Each controller includes a synchronous counter and control logic circuitry. The control logic generates at least one synchronization output signal based on the outputs of the counter and the programming state (i.e., master or slave) of the controller. The master controller generates a master clock signal having a synchronizing state encoded thereon and provides the master clock to the slave controller, which includes synchronization circuitry for receiving the master clock and resetting the counter based on the synchronizing state of the master clock, thereby assuring that appropriate phase relationships are maintained between the controller outputs.

Abstract: A pulse width modulator (305) for driving a load in a multi-phased power system having circuitry (270) responsive to channel signals for providing an average signal by summing the channel signals at a node (221) which is coupled with a plurality of resistive elements, and having further circuitry for providing an error between said load and said reference potential, and having still further circuitry (250) for summing the channel signals, average signal, and error for providing a respective drive signal for each of the power switches, wherein the error signal and the average signal have complementary effects on a duty factor of the drive signals and the channel signal has an effect contrary to the error signal and the average signal. Further, a plurality of pulse width modulators (305) can be combined as a system (300) by connecting respective nodes (221) for providing current sharing between all phases.