Abstract: Electrical apparatus (20) includes an inverter (24) having input terminals for receiving DC input power and output terminals for coupling to an AC power grid. A pulse-width modulation (PWM) generator and drivers (26) drive the switches so as to control respective amplitudes, frequencies, and phases of the output current waveforms of the inverter. Control circuitry (28) receives measurements of respective time-varying voltages and currents on the input and output terminals, computes a model (40) that includes three virtual currents flowing in a synchronous machine that is emulated by the apparatus, wherein the three virtual currents are associated respectively with the three output current waveforms, and controls the PWM generator and drivers responsively to the three virtual currents so as to synchronize the amplitudes, frequencies, and phases of the three output current waveforms of the inverter with the three phases of the AC power grid.

Abstract: A blanking die apparatus includes a first blanking die including an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. A second blanking die includes an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. The second blanking die movable on a base in a feed direction to increase and decrease a dimension of a blank formed between the first blanking die and the second blanking die.

Abstract: A blanking die apparatus includes a first blanking die including an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. A second blanking die including an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. An infeed assembly that is configured to form a continuous strip of a metal sheet into a non-planar, arc-shape as the continuous strip of metal sheet enters the first blanking die.

Abstract: A laser containment system in which a platform is suspended above a table on which laser light experiments will be performed. A number of curtain pockets having U-shaped cross sections are mounted beneath the platform, with the pocket openings facing down toward the sides of the table. A roller is mounted between end walls inside each pocket, and a laser curtain long enough to be lowered past a corresponding side of the table is wound on each roller. A clutch supported on an end wall of each pocket operatively engages an end of the roller inside the pocket to lower or raise the curtain on the roller. An associated clutch pulley is disposed outside the end wall of each pocket on which the clutch is supported. A curtain chain engages the circumference of the pulley, and the chain hangs outside the curtain when lowered for access by a user.

Abstract: A blanking die apparatus includes a first blanking die including an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. A second blanking die includes an upper die shoe including an upper die shoe cutting surface and a lower die shoe comprising a lower die shoe cutting surface. The second blanking die movable on a base in a feed direction to increase and decrease a dimension of a blank formed between the first blanking die and the second blanking die.

Abstract: A blanking die apparatus includes a first blanking die including an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. A second blanking die including an upper die shoe including an upper die shoe cutting surface and a lower die shoe including a lower die shoe cutting surface. An infeed assembly that is configured to form a continuous strip of a metal sheet into a non-planar, arc-shape as the continuous strip of metal sheet enters the first blanking die.

Abstract: Apparatus (22, 90) for controlling DC voltage on a bus (26) includes a switched power converter (32), including a pair of terminals (31) for connection between the bus and a ground (28), a buffering capacitor (48), and switching circuitry (36) configured to control a voltage between the terminals while a charge on the buffering capacitor varies over a predefined range in response to a current flowing through the terminals. A control circuit (50, 98) is coupled to monitor the voltage between the terminals, the current, and a voltage on the buffering capacitor, and is configured to adjust the voltage between the terminals by controlling the switching circuitry in response to changes in the monitored voltages and current so that the terminal voltage is maintained at a reference voltage value, which can be adjusted adaptively so as to converge to the equilibrium voltage of the DC bus. Consequently, the apparatus need have only two terminals, and hence is easy to install.

Abstract: An apparatus for controlling ripple voltage on a bus includes a switched power converter and a control circuit. The switched power converter includes a pair of terminals for connection between the bus and a ground, a buffer capacitor, an inductor, and switching circuitry coupled to the buffer capacitor and the inductor. The switching circuitry is configured to control a voltage between the terminals while a charge on the buffer capacitor varies over a predefined range in response to a current flowing through the terminals. The control circuit is configured to adjust the voltage between the terminals by controlling the switching circuitry while maintaining bipolar current flow through the inductor in all working conditions of DC voltage and power flow.

Abstract: A laser containment system in which a platform is suspended above a table on which laser light experiments will be performed. A number of curtain pockets having U-shaped cross sections are mounted beneath the platform, with the pocket openings facing down toward the sides of the table. A roller is mounted between end walls inside each pocket, and a laser curtain long enough to be lowered past a corresponding side of the table is wound on each roller. A clutch supported on an end wall of each pocket operatively engages an end of the roller inside the pocket to lower or raise the curtain on the roller. An associated clutch pulley is disposed outside the end wall of each pocket on which the clutch is supported. A curtain chain engages the circumference of the pulley, and the chain hangs outside the curtain when lowered for access by a user.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A test fixture has a flexible plastic cable that acts as a waveguide. The Device-Under-Test (DUT) is a small transceiver and antenna that operate in the Extremely High-Frequency (EHF) band of 30-300 GHz. The size of the DUT transceiver is very small, limiting the power of emitted electromagnetic radiation so that close-proximity communication is used. The envelope for reception may only extend for about a centimeter from the DUT transceiver, about the same size as the test socket. A slot is formed in the test socket very near to the antenna. The slot receives one end of the plastic waveguide. The slot extends into the envelope by the DUT transceiver so that close-proximity radiation is captured by the plastic waveguide. The waveguide has a high relative permittivity and reflective metalized walls so that the radiation may be carried to a receiver that is outside the envelope.

Abstract: A method of controlling an inverter, by modelling a synchronous generator is provided.

Abstract: A commercial and social system is controlled by collecting information related to historical events from veterans and active duty personnel. The historical events are stored in a database as keypoints based on time and location. Personal profile information for the veterans and active duty personnel is also collected and stored in the database. The information stored in the database is accessed based on search selections. A timeline of the historical events is presented based upon matches between the search selections and information stored in the database. A veteran or active duty personnel associated with the historical events is identified. A connection to the identified veteran or active duty personnel is controlled to enable a commercial or social activity with the identified veteran or active duty personnel. The historical events can also relate to sport teams, corporations, professional organizations, government, schools, and other organizations with numerous members.

Abstract: Device, system and method of protecting aircrafts against incoming threats. For example, a system for protecting an aircraft against an incoming threat includes: one or more electro-optic sensors to substantially continuously search for the incoming threat, and to generate a signal indicating that a possible incoming threat is detected; one or more radar sensors to be activated in response to the signal, and to search for the incoming threat; and a central computer to determine whether or not the incoming threat exists, based on a sensor fusion algorithm able to fuse data received from the one or more electro-optic sensors and data received from the one or more radar sensors.

Abstract: The invention is concerned with a device and a method for controlling an inverter associated with a power source, which typically will be a distributed power source. The role of an inverter is to modulate the electrical power output, e.g. to provide a three phase AC electrical output at suitable voltage, where the output is to be supplied to a conventional power distribution, grid. The invention involves modelling the behaviour of a synchronous electrical generator. Variables represent the angular position and rotational speed of the virtual rotor (14) of this virtual synchronous generator. The torque electromagnetically exerted on the rotor is calculated from a measured inverter output current, and from a variable representing excitation current in the rotor.