Texas Instruments Corporation

International Business Machines Corporation

Robert Edward Jansen

Mark David Heminger

Gary Dale Carpenter

Eric Gregory Oettinger

Mark David Hagen

John Jeffrey Stephenson

Eugene Francis Plutowski

Lawrence P Segar

Warren A Lopour

A PFC circuit modulating a power line using pulse width modulation (PWM) to drive a power MOSFET and series inductor across the power line. Since many modern electronic systems include a power factor correction circuit (PFC) that already includes a series inductor and power MOSFET, a PLC is incorporated into a controller to inject a PLC transmit signal into a control loop for the PFC circuit. This can be done using either an analog PFC controller, such as the UCC28517, the UCC2819A, or a digital PFC controller such as based on a TMS320C24xx DSP.

Power line communication using power factor correction circuits

A method of eliminating the non-linearities associated with the remote feedback sensor, such as a quad position detector, used in a micro-electro-mechanical (MEM) mirror assembly. The incoming beam transmitted from a remote optical wireless link is first polarized, and then a single detector is employed to detect the polarization for the receiver. The single detector eliminates the non-linearity associated with a quad position detector, since the space between the quad detectors is eliminated.

Position demodulation through polarization of the transmitted beam in an optical wireless link

Micro-electromechanical apparatus and method with position sensor compensation to compensate for sensor drift. A preferred embodiment comprises modifying the intensity of a light source used in position detection to maintain a constant sum of the voltages output from photodetectors receiving light from the light source. Preferred embodiments may be implemented in digital signal processor code, or external to the processor in analog circuitry. By adjusting light source intensity, position calculations may be performed without normalization, and thus without a time-consuming division operation.

Micro-electromechanical apparatus and method with position sensor compensation

Signal conversion apparatus and method with coarse and fine digital to analog converters. The output of the coarse DAC has a high gain to support wide voltage swings, while the fine DAC has a low gain to support accurate tracking control. The two outputs are combined in an analog summing junction. The apparatus and method may comprise a low pass filter connected to the coarse DAC output. The filter may be switched off during large changes to provide rapid system response, and switched on during position holding to attenuate noise from the coarse DAC. The apparatus and method may comprise a pre-charging capacitor in the filter, wherein the capacitor may be pre-charged when the filter is off, reducing the switch transient when the filter is switched on.

Signal conversion using coarse and fine digital to analog converters

A method of operating bridge circuit for control of an inductive load is disclosed. The bridge circuit has a pair of input terminals for connection across a power source and a pair of output terminals for connection across the inductive load. Each arm of the bridge includes a transistor switch connecting an input terminal with an output terminal. Clamp circuits are connected to each pair of input and output terminals, taking inputs therefrom and responding to a transition through a predetermined voltage differential between the terminals for driving the transistor switch connecting the output terminal to the remaining input terminal, thereby limiting the output terminal to a predetermined voltage level.

Method and system for actuator control for direct access storage devices

A disk file having on one side of a disk a servo track and a plurality of data tracks all equally spaced on centers and a carriage translatable across the disk and having an array of read/write heads some of which are spaced on centers for the distance equal to the spacing between adjacent ones of said tracks and others of which are spaced on centers for multiples of the distance between adjacent ones of said tracks, the spacing between heads being such that when said heads are successively in alignment with said servo track the others of said heads are aligned with said data tracks.

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Byron, MN, United States of America

Robert Edward Jansen