International Business Machines Corporation

Tuan D Ngo

King M Chu

William M Lorenz

Prabjit Singh

Gerald J Fahr

Gerard Vincent Weber, Jr

Andrew Rybak

Eric N Chikando

Kwok M Soohoo

Brad E Dillon

Joseph W Bogdanski

William J Roberts

Eric R Schumann

Ronald L Underwood

William T Winkler

John P McConnell

Tuning a programmable power line filter, the power line filter including a live line, a neutral line, and a ground line connected to input terminals of the filter on an input side of the filter, the live line and the neutral line connected through inductors in the filter to output terminals on an output side of the filter, X-capacitors selectably connected through tuning switches between the live line and the neutral line, Y-capacitors selectably connected through tuning switches between the live line and ground and/or between the neutral line and ground, and a tuning control circuit connected to the tuning switches and selectably connected through one or more programming switches to the load, including measuring by the tuning control circuit the input impedance of the load and programming by the tuning control circuit the tuning switches in dependence upon the input impedance of the load.

Tuning a programmable power line filter

A system for injecting noise signals onto power generated by a power source comprising: a voltage source; a device under test having a power input in operable communication with the noise introduction apparatus; and a noise introduction apparatus interposed between the power source and device under test in operable communication with the voltage source, the noise introduction apparatus comprising, a switching device configured to provide a low impedance conductive path when commanded, and a current limiting device in series with the switching device, the current limiting device configured to provide a low impedance conductivity for a selected current and a selected duration. The switching device and current limiting device cooperate to shunt the voltage source to the power input.

Method and apparatus for evaluating susceptibility to common mode noise in a computer system

The power supply of equipment being tested for common mode noise problems is connected to a source of power with the power and neutral input terminals of the power supply isolated from the power ground. Recorded common mode noise signals are then inserted between the power supply's neutral input terminal and power ground to produce problem conditions. When the cause of the problem conditions are identified, steps are taken to eliminate the condition.

Apparatus and method for testing computer equipment for susceptibility to neutral to ground noise

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Poughkeepsie, NY, United States of America

Tuan D Ngo