Abstract: A system for degaussing a magnetized structure can include a given circuit that provides a differential alternating current (AC) signal that decays from an upper level to a lower level over a predetermined amount of time. The system also includes a given electrical coil coupled to the given circuit. The electrical coil circumscribes the magnetized structure. The electrical coil induces a decaying magnetic field on the magnetized structure in response to the differential AC signal to convert the magnetized structure into a degaussed structure.

Abstract: An AC-DC power converter has a phase-shifting autotransformer based rectifiers and DC capacitors. Soft start of the AC-DC power converter is achieved by designing the autotransformer to operate at a low peak flux density at a point of AC voltage step application (initial turn on). The addition of a controlled impedance segregates capacitor charging from the initial magnetizing process of the autotransformer.

Abstract: According to one embodiment, a power conversion apparatus determines a peak value of circuit current in each pulse cycle, from a corrected output voltage value by subtracting a predetermined reference voltage from an output voltage detected by the output voltage detector, and an input voltage detected by the input voltage detector. The pulse signal output unit outputs a pulse signal to the first switch when the polarity of input voltage is positive, and outputs a pulse signal to the second switch when the polarity of input voltage is negative. A pulse signal turns on in synchronization with a clock signal input from the oscillator, and is kept on until the circuit current detected by the circuit current detector reaches the peak value. A pulse signal turns off when the circuit current reaches the peak value, and turns on again in synchronization with the next clock signal.

Abstract: The systems and methods described herein provide for a universal controller capable of controlling multiple types of three phase, two and three level power converters. The universal controller is capable of controlling the power converter in any quadrant of the PQ domain. The universal controller can include a region selection unit, an input selection unit, a reference signal source unit and a control core. The control core can be implemented using one-cycle control, average current mode control, current mode control or sliding mode control and the like. The controller can be configured to control different types of power converters by adjusting the reference signal source. Also provided are multiple modulation methods for controlling the power converter.

Abstract: A method and apparatus for converting three phase AC voltages on first, second and third input lines to DC voltage across positive and negative DC buses, the apparatus comprising a rectifier including first, second and third rectifier legs, each leg including a switch and a diode wherein the switch is linked between the positive DC bus and an cathode of the diode, an anode of the diode is linked to the negative DC rail and the first, second and third diode cathodes are linked to the first, second and third input lines, respectively, a DC bus voltage sensor linked to the positive DC bus and measuring the DC bus voltage to generate a measured DC bus voltage and a rectifier controller that receives the measured DC bus voltage, a reference voltage value and the three phase AC voltages wherein, when the measured DC bus voltage is at least equal to the reference voltage value, the controller turns on the switches in the first, second and third rectifier legs when the voltages on the first, second and third input li

Abstract: The systems and methods described herein provide for a universal controller capable of controlling multiple types of three phase, two and three level power converters. The universal controller is capable of controlling the power converter in any quadrant of the PQ domain. The universal controller can include a region selection unit, an input selection unit, a reference signal source unit and a control core. The control core can be implemented using one-cycle control, average current mode control, current mode control or sliding mode control and the like. The controller can be configured to control different types of power converters by adjusting the reference signal source. Also provided are multiple modulation methods for controlling the power converter.

Abstract: Control of an AC-to-DC power supply assembly fed by a three-phase AC source is provided by: determining whether the power supply assembly includes greater than three single-phase power regulators feeding a common load, with multiple regulators being connected in parallel across a common phase of the AC source, and if so, summing currents provided by the regulators to the common load; and ascertaining whether the summed current is less than a predefined threshold, and if yes, operating the power supply assembly in a line balance mode to maintain power drawn on the phases of the AC source in balance, and if greater than the predefined threshold, operating the power supply assembly in a maximize power mode wherein power is provided to the common load without maintaining power drawn on the phases of the AC source in balance.

Abstract: In one embodiment, a load connected to power sourcing equipment (PSE) compatible with a Power over Ethernet (PoE) standard is characterized to determine whether the load corresponds to a valid powered device (PD). A switching signal having a first frequency is generated on the isolated side and used to generate an electrical current through the isolated-side primary coil of a power transformer in the PSE. A first voltage measurement, corresponding to a first line-side voltage across the transformer's secondary coil, is generated on the isolated side, e.g., using an isolated-side auxiliary transformer coil. The load is characterized based on the first voltage measurement and the first frequency. To compensate for voltage offset, a second voltage measurement can be generated corresponding to a second frequency of the switching signal, where the load is then characterized based on the first and second voltage measurements and frequencies.

Abstract: An apparatus having a rectifier topology for use on a three-phase electrical system is disclosed. The apparatus includes an input filter at each phase, a rectifier set at each phase in power communication with and downstream of each respective input filter, and a separate and independent booster section at each phase in power communication with and downstream of each respective rectifier set. Each booster section comprises two switches, thereby providing a six-switch three-level discontinuous conduction mode (DCM) boost rectifier.

Abstract: The systems and methods described herein provide for a universal controller capable of controlling multiple types of three phase, two and three level power converters. The universal controller is capable of controlling the power converter in any quadrant of the PQ domain. The universal controller can include a region selection unit, an input selection unit, a reference signal source unit and a control core. The control core can be implemented using one-cycle control, average current mode control, current mode control or sliding mode control and the like. The controller can be configured to control different types of power converters by adjusting the reference signal source. Also provided are multiple modulation methods for controlling the power converter.

Abstract: A heater lamp control apparatus and method of detecting an input AC voltage and providing a pulse signal corresponding thereto, includes an AC voltage phase detection unit to detect a phase of the inputted AC voltage when a magnitude of the inputted AC voltage is over a predetermined level. The heater lamp control apparatus also includes a pulse signal generation unit to generate a pulse reference signal based on a result of the detection, a pulse delay signal that is phase-delayed, and a heater lamp control pulse signal based on a result of the comparison of the magnitudes of the pulse reference signal and the pulse delay signal. The heater lamp control pulse signal includes a control unit to control a drive-timing of the heater lamp based on the heater lamp control pulse signal. Thus, the heater lamp control apparatus minimizes a flickering phenomenon as well as an amount of electric power consumed in a heater lamp.

Abstract: A ground power unit for providing dc power for aircraft includes a source of 3-phase ac power and a transformer/rectifier arrangement for converting 3-phase ac power to dc power. The transformer/rectifier arrangement includes an A-phase transformer formed by an A-phase magnetic member, an A-phase primary winding having first and second sides, and an A-phase secondary winding; a B-phase transformer formed by a B-phase magnetic member, a B-phase primary winding having first and second sides, and a B-phase secondary winding; and a C-phase transformer formed by a C-phase magnetic member, a C-phase primary winding having first and second sides, and a C-phase secondary winding. The A-phase primary winding first side is connected to receive A-phase power, the B-phase primary winding first side is connected to receive B-phase power, and the C-phase primary winding first side is connected to receive C-phase power.

Abstract: A short circuit current limiting reactor is disclosed having a series pass inductor wound on a core. A saturation control circuit is employed to control the magnetic saturation of the core. Under normal operating conditions, the core is in magnetic saturation thus making the reactance of the inductor negligible and allowing an AC current to flow freely through the inductor. Upon the occurrence of a short circuit fault, the saturation control circuit brings the core out of its magnetically saturated state thereby causing the reactance of the inductor to rise and limiting the amount of current flowing through the inductor.

Abstract: A power supply (100) for producing a regulated output DC voltage from an AC voltage source (12) having at least one phase (14); a fullwave rectifier (16) coupled to the AC voltage source for producing a rectified output voltage potential, the fullwave rectifier having a number of pairs of diodes (D1-D6) equal to a number of phases of the AC voltage source; a number of pairs of magnetic amplifiers S1-S6 equal to a number of phases of the AC voltage source, each magnetic amplifier having a control input for varying an impedance between an input and an output in response to variation of a control signal; a control (36), responsive to the output voltage, for producing the control signal in response to the output voltage to cancel any variation in the output voltage from a regulated voltage; a fault detection circuit, responsive to an electrical load drawing current from the power supply for producing a shutdown signal; and a circuit, coupled to one of the magnetic amplifiers of each of the phases, responsive to t

Abstract: A multi-voltage transformer input circuit, which may have multi-phase input, and where the input or each phase of the input has a primary reactor voltage control, is provided by the present invention. The primary winding of the transformer, or each phase of the primary winding has at least two sections which are bifilar wound on a single core, each section having its own polarity. Each primary winding section is connected with one of a pair of like synchronous operating current control devices, which may be saturable core reactors, magnetic amplifier, or phase-angle fired silicon controlled rectifiers. Each synchronous operating device is in series with its respective primary winding section, the first in opposite polarity to the first primary winding section, the second with the same polarity as the second primary winding section.

Abstract: A high power D.C. supply regulated for constant output power to be dissipated in varying loads such as encountered in cathode sputtering systems. A.C. input power is rectified to produce the desired D.C. The output D.C. voltage and load current are measured and a voltage signal proportional to their product is compared with a D.C. input control signal. The comparator "error" output signal controls a pass element that varies a D.C. current through saturable reactors in the A.C. input power lines to regulate the D.C. power into the load. The supply includes a limiting feature that is adjustable to a desired threshold level for limiting D.C. output power, voltage, and/or current so that the limiter will take control from the comparator to hold the supply output at a safe level.

Abstract: Power supply of the saturable reactor type is disclosed. The improvement is the inclusion of a variable impedance network, such as a pair of opposed semiconductor controlled rectifiers, in series with the current winding of the saturable reactor. Also included is an electronic circuit for changing the impedance of the variable impedance circuit, such as a control circuit for monitoring an operating parameter and for enabling or disabling the firing of the semiconductor controlled rectifiers in response to a change in the operating parameter. A preferred embodiment of the power supply also includes a transformer and a rectifier for supplying high-voltage, direct current to a sputtering apparatus.