Abstract:
A variable attenuator and method of attenuating a signal is presented. The variable attenuator contains an input that receives an input signal to be attenuated. A voltage divider between a resistor and parallel MOSFETs provides the attenuated input signal. The MOSFETs have different sizes and have gates that are connected to a control signal through different resistances such that the larger the MOSFET, the larger the resistance. The control signal is dependent on the output of the attenuator. The arrangement extends the linearity of the attenuation over a wide voltage range of the control signal and decreases the intermodulation distortion of the attenuator.
Abstract:
A system and method for performance monitoring in processors is provided. The system and method evaluates the performance of the processor by counting selected events during one or more defined periods. The performance monitor provides improved performance characterization by providing highly-configurable start-stop control over the event counting.
Abstract:
A variable reluctance load cell for measuring the static or slowly fluctuating load, or tension, on devices is contained in a support tube. A sensor in the tube utilizes opposing C and I shaped magnetic cores attached to opposing ends of the support tube. A magnetic circuit is formed having an inductance defined by the size of the gap between the magnetic cores with the reluctance dominated by the gap. The sensor inductance is coupled with a fixed, predetermined capacitance in a resonant LC circuit, and the resonant frequency is a function of the gap. The sensor is in a cavity within the tube, and the cavity is sealed in a manner that prevents water or other damaging agents from entering the sensor. In this manner, mounting the sensor and tube to a static device and measuring the AC voltage at the sensor, the amount of load, or stress can be determined.
Abstract:
A dissolving tank for dissolving a large amount of gas in a liquid and including a generally horizontally disposed tray (28) (29) mounted within the tank (2) (21) to divide the tank (2) (21) into an upper reaction zone (36) and a lower discharge zone (38). The tray (28) (29) has formed therein both a central opening (34) (35) for fluid communication between the discharge zone (38) and the reaction zone (36) and peripheral openings (32) (33) which allow any liquid which collects on the tray (28) (29) to flow from reaction zone (36) to discharge zone (38). The dissolving tank further includes liquid feed means (10) positioned within the tank (2) (21) below the tray (28) (29) to discharge liquid upwardly through the central opening (34) (35) of the tray (28) (29) and into the reaction zone (36). The dissolving tank further includes liquid distribution means (14) mounted within the tank (2) (21) above the tray (28) (29) and having flared sidewalls (15) and a vertically-oriented distribution orifice (16). The distribution means (14) is positioned so that a portion of the liquid discharged upwardly from the feed means (10) impacts on the flared sidewalls (15) and is distributed as droplets within the reaction zone (36) and another portion of the liquid discharged from the feed means (10) passes upwardly through the distribution orifice (16) toward the top (3) of the tank (2) (21).
Abstract:
An amplifier, tuner, and method of amplification are provided. The amplifier has a pair of transistors. Each transistor has a control terminal and an output terminal disposed between the transistor and a power supply input. A first network is connected between each power supply input and output terminal. The first network contains a first resistor and a first switch connected in parallel with the first resistor. A second network is connected between the transistors. The second network contains a first and second combination. Each of the first and second combinations contains a second resistor and a second switch connected in parallel with the second resistor. The first and second combinations are connected by a third switch.
Abstract:
A frequency source having a fast start-up time and low noise in steady state is presented. The frequency source includes an oscillator and a hybrid automatic gain control (AGC) loop that switches between an analog AGC loop at oscillator start up and a digital AGC loop at steady state operation. The analog AGC loop includes a peak detector connected to the oscillator and an error integrator integrating the difference between the peak detector output and a reference voltage. The digital AGC loop includes a comparator comparing the peak detector output and high/low reference voltages, an oscillator counter providing a timer signal, a digital-to-analog converter (DAC) supplied with a digital word, and a low pass filter between the DAC and the oscillator. The timer signal causes a multiplexer to select either the analog AGC loop or the digital AGC loop.
Abstract:
An improved process for the alkylation of benzene in the presence of an alkylation catalyst. The catalyst bed may be caused to move in a direction countercurrent to the movement of the benzene and olefin, or a portion of the catalyst bed is periodically removed and replaced. A regeneration step, whereby the catalyst is heated in a controlled oxygen atmosphere in order to reactivate the catalyst, is also described.