Lucent Technologies Inc.

At&t Bell Laboratories

Victor K Lee

Jin He

Greg H Fasullo

Greg P Jorgenson

Rui Liu

Qing Chen

An Ba Nguyen

Donald B Rose

For use with a DC fan, a detection circuit and a method of detecting an operational condition thereof. In one embodiment, the detection circuit includes: (1) a sensor, coupled to the DC fan, that senses a current through the sensorless DC fan and produces an intermediate signal based thereon and (2) an alarm circuit, coupled to the sensor, that compares the intermediate signal to a range defined by an upper limit signal and a lower limit signal and generates an alarm signal when the intermediate signal is outside of the range.

Fan operation detection circuit for a DC fan and method of operation

For use with a DC power supply having first and second output rectifying circuits couplable in alternative configurations to provide dual voltages at an output of the DC power supply, an adaptive voltage controller and a method of adaptively controlling the output voltage. In one embodiment, the adaptive voltage controller includes: (1) a configuration determination circuit, coupled to the output, that generates a configuration signal that is a function of a configuration of the first and second output rectifying circuits, (2) a voltage feedback circuit, coupled to the configuration determination circuit, that develops a voltage feedback signal based on the configuration signal and (3) a voltage control circuit, coupled to the voltage feedback circuit, that receives the voltage feedback signal and controls an output voltage of the DC power supply as a function thereof.

Power supply with re-configurable outputs for different output voltages

Faceplate for a module

For use in a power converter having a rectifier coupled to an output thereof, a snubber circuit including an energy storage device coupled to the rectifier that moderates a voltage across the rectifier and a method of moderating the voltage. In one embodiment, the snubber circuit includes: (1) a first switch that regulates a voltage across the energy storage device, (2) an inductor, coupled to the first switch, that provides a discharge path for energy stored in the energy storage device when the first switch is conducting and (3) a second switch that recovers energy stored in the inductor to the output when the first switch is not conducting. The snubber circuit thereby reduces voltage stress across the rectifier during a current limit mode of operation.

Snubber circuit for a rectifier and method of operation thereof

Magnetic-free DC/DC converters, methods of operation thereof and a computer system employing at least one converter. In one embodiment, the converter includes: (1) an input capacitor coupled to a DC input of the converter, (2) a first switch coupled between the input capacitor and an output of the converter to transfer electrical power from the DC input to the output when the first switch is closed, (3) an output capacitor coupled in parallel with the output of the converter, (4) a second switch coupled in parallel with the input capacitor to short the input capacitor when the second switch is closed and (5) a switching controller circuit, coupled to the first and second switches, that provides complementary control signals to the first and second switches that are a function of an output voltage of the converter.

Magnetic-free DC/DC converter and method of operation thereof

A common mode lightning protection circuit includes a series circuit including a Y-capacitor and breakdown device connected between a current carrying input line and the frame ground of the power supply. This arrangement permits the ready application of current carrying line-to-frame ground dielectric tests needed to meet predefined safety requirements.

Growing community of inventors

Plano, TX, United States of America

Victor K Lee