Abstract: A system for limiting AC inrush current to a power supply. The system comprises first, second, and third windings magnetically coupled to a core of a transformer of the power supply. The system also comprises a first low-voltage contactor and a second low-voltage contactor. The system further comprises a first low-voltage impedance element connected between the first low-voltage contactor and the first winding, a second low-voltage impedance element connected between the second low-voltage contactor and the first winding, a third low-voltage impedance element connected between the first low-voltage contactor and the second winding, and a fourth low-voltage impedance element connected between the second low-voltage contactor and the second winding.

Abstract: Use of a foam control laser having a wavelength corresponding to a mode specific peak of the absorption spectrum of a liquid constituent of the form greatly increases the efficiency of foam control.

Abstract: Improved binoculars are provided for viewing objects at a distance and for selectively recording a digital image of the objects. The binoculars include first and second monoculars each with an optical lightpath constructed to deliver an image of the object to one eye of the observer. Included within one of the monoculars is a beamsplitter designed to allow a portion of the light in the first optical lightpath to pass to the eye of the observer and to reflect a second portion of the light. The reflected portion of the light is directed to a digital image sensor and recording device. The other monocular includes compensating optics, such as a second beamsplitter, to alter the image to correct for the refraction and decrease in light intensity caused by the beamsplitter in the first light path. The second monocular does not include an image sensor and does not include an image recording device.

Abstract: A hybrid tap-changer for delivering AC power to a load in which a high-power tap-changing transformer with full range of adjustment but limited resolution is combined with a low-power electronic converter of limited range but high resolution to provide a tap-changing transformer with high resolution.

Abstract: This invention is an improvement to a multi-level, multi-phase power supply. Typically, in such power supplies, each of the phases has one or more power cells providing a pulse width modulated output. In such a configuration, when the transition of the pulse width modulated outputs of corresponding power cells in different phases occurs simultaneously, a double step in voltage is observed on the output of the power cell. This invention is an improvement over the prior art wherein the transitions of the outputs of the power cells are controlled to avoid simultaneous transitions.

Abstract: A hybrid tap-changer for delivering AC power to a load in which a high-power tap-changing transformer with full range of adjustment but limited resolution is combined with a low-power electronic converter of limited range but high resolution to provide a tap-changing transformer with high resolution.

Abstract: This invention is an improvement to a multi-level, multi-phase power supply. Typically, in such power supplies, each of the phases has one or more power cells providing a pulse width modulated output. In such a configuration, when the transition of the pulse width modulated outputs of corresponding power cells in different phases occurs simultaneously, a double step in voltage is observed on the output of the power cell. This invention is an improvement over the prior art wherein the transitions of the outputs of the power cells are controlled to avoid simultaneous transitions.

Abstract: A power supply apparatus and method for supplying direct current power to low and medium voltage DC loads wherein a multi-phase transformer having multiple secondary windings provides multi-phase power to multiple power cells, each of which have a single DC output and are controllable by a modulation controller. The primary and secondary windings in the power transformer may be star- or mesh-connected; the secondary windings may be shifted in phase. Because the power cells can be connected in series, the maximum output voltage for each cell may be less than the maximum line-to-line voltage. The power cell output can have variable DC voltage and current which can be controlled using pulse-width modulation techniques. AC input power is converted to DC output power for each power output line. Output power modulation can be produced by interdigitating a selected number of carrier signals so that harmonic components reflected back to the input are attenuated.

Abstract: A high frequency ultrasonic system for sonically removing particles from substrates or wafers held in a carrier or carriers in a tank of liquid, such as DI water. A frame encompasses the tank and supports the transducer housing at an angle with respect to the tank bottom and also provides for horizontal movement between the sides of the tank. A transducer housing supports at least one transducer within the transducer housing. The transducer housing can be supported and moved at an angle with respect to the tank bottom.