Abstract: A technique for performing signal integrity analysis of a system includes providing a stimulus pattern and a model of the system and performing analog simulation of the model utilizing the stimulus pattern. The stimulus pattern includes sequences of signal transitions with associated transition times and the sequences of signal transitions conform to a bus protocol and the associated transition times are according to characteristics of the system. The stimulus pattern is generated by initializing each of the sequences of signal transitions to an initial signal value and the associated transition times to an initial time, generating subsequent signal values and subsequent transition times by applying protocol rules and calculating timing adjustments for each of a list of transactions; the subsequent signal values and subsequent transition times to be added to the sequences of signal transitions.

Abstract: A thermal management of a computer system may be advantageously obtained by predicting temperature variations based upon past temperature readings. Such a system may, in preferred embodiments, filter the past temperature data to provide a more precise value, allow for a floating trip level that will change with the rate of temperature change and even allow for prediction of the amount of time left before a system shutdown may occur.

Abstract: A multiple fan system including at least two simultaneously operated fans. Each of the fans are operable as a constant speed fan and as an oscillating speed fan. Not more than one of the fans is operated as a constant speed fan. Each fan not being operated as a constant speed fan is operated as an oscillating speed fan. A fan controller operates each oscillating speed fan in a mode whereby a respective acoustic emission having a range of frequency different than any other oscillating speed fans is produced.

Abstract: A multiple fan system including at least two simultaneously operated fans. Each of the fans are operable as a constant speed fan and as an oscillating speed fan. Not more than one of the fans is operated as a constant speed fan. Each fan not being operated as a constant speed fan is operated as an oscillating speed fan. A fan controller operates each oscillating speed fan in a mode whereby a respective acoustic emission having a range of frequency different than any other oscillating speed fans is produced.

Abstract: A multiple fan system including at least two simultaneously operated fans. Each of the fans are operable as a constant speed fan and as an oscillating speed fan. Not more than one of the fans is operated as a constant speed fan. Each fan not being operated as a constant speed fan is operated as an oscillating speed fan. A fan controller operates each oscillating speed fan in a mode whereby a respective acoustic emission having a range of frequency different than any other oscillating speed fans is produced.

Abstract: A process control system according to the present invention uses analog control circuitry in which a differential amplifier stage is incorporated into the feedback path rather that the feedforward path to enable the control of highly non-linear processes that may also exhibit high levels of hysteresis. Such processes often have superior performance characteristics that conventional control circuitry cannot exploit. The present invention additionally incorporates an automatic control circuit which varies the gain of various stages the control circuitry when the output of the process is within a predetermined range. An embodiment of the present invention is used to control a nonlinear proportional valve with severe hysteresis. The valve regulates the pressure within pressure-driven ophthalmic surgical instruments, which must be controlled extremely precisely to enable successful eye surgery.