The Babcock & Wilcox Company

Elsag International B.v.

Edward Bastijanic

John W Robertson, Jr

Edward L Sterling, Jr

John J Fry

David J Wroblewski

Richard J Molnar

Rowland E Whitford

Gary S Thomas

Timothy B McGlinchy

Process command controller

A connector for a power module to selectively engage metallic pads positioned on the backplate printed circuit board is disclosed. The connector includes a first set of contacts and a second set of contacts positioned such that the first set of contacts makes engagement with the metallic pads before the second set of contacts make such engagement. The contacts are capable of carrying relatively high current.

Surface contact power connector

An overcurrent protection system for AC motor control systems which provides a separate overcurrent shut down mechanism for each phase of the AC power used in an AC motor. These separate phase shutdown mechanisms provide protection for minor overcurrent conditions without shutting down the entire motor control system. The overcurrent protection system also provides a mechanical feedback apparatus for totally shutting down the motor control system only in a severe overcurrent condition.

Current fault detection system and method for AC controller

A convertor for converting an analog signal to a digital pulse comprises a switching capacitor which is charged by a differential analog signal supplied to the switching capacitor over an input circuit. The capacitor is discharged over an output circuit with the aid of a constant current supply. The charge level of the capacitor is proportional to the analog signal so that the time it takes the capacitor to discharge to a selected low charge level, is proportional to the analog signal. This time period is used by a microprocessor control to generate a digital pulse having a pulse equal to the discharge time for the capacitor. The microprocessor also selectively connects the input and output circuits to the capacitor for respectively charging and discharging the capacitor.

Low level voltage pulse-converter

An improved power supply for power switches arranged in a totem pole configuration is disclosed. A single power supply, having an output voltage substantially less than the voltage applied to the upper power switch, periodically charges a capacitor within a flying capacitor circuit. Microprocessor based control circuitry controls the charging and discharging of the capacitor and the periodic operation of the power switches resulting in the voltage at the output of the power switches being at system common or at the voltage applied to the upper power switch.

Power supply for totem pole power switches

A pressure transmitter assembly comprises a pressure transducer having a pair of inputs each connected to a separate pressure line. A valve is connected in each pressure line. A pressure equalizing line is connected between the pressure lines at a point between the valves and the pressure transducer. The pressure equalization line is provided with an equalization valve. All three valves are connected to a switching circuit which is controlled by a microprocessor. The switching circuit functions to open both of the valves in the pressure lines while closing the equalizing valves so that the pressure transducer is exposed to two separate pressure and generates a signal corresponding to a difference in two separate pressures. To zero the transducer and recalibrate the transmitter, the low pressure line valve is closed while the equalizing valve is opened. This equalizes the pressure between the two pressure lines so that any signal from the transducer corresponds to a zero pressure difference value.

Self-zeroing pressure transmitter with automatic pressure manifold

A serial communication interface establishes communication between the microprocessor of a transmitter, to a current loop powered by a power supply. The microprocessor outputs an analog signal corresponding to a process variable and also outputs a serial communication voltage pulse signal. The analog signal is applied to a current regulating circuit which draws current from the power supply onto the current loop in an amount proportional to the process variable. A comparator has one input connected to the microprocessor for receiving the serial communication voltage pulse signal and another input for receiving a fixed selected voltage. The output of the comparator is connected to an input of the current regulating circuit in such a way so that a signal from the comparator is summed with the analog signal. The output signal of the comparator is modulated in synchronism with the voltage pulses and represents a fraction of the analog signal so that both signals can be supplied to the current loop simultaneously.

On-line serial communication interface from a transmitter to a current

A current regulating convertor includes a pulse generator which generates a voltage pulse train having a variable duty cycle. A low pass filter is connected to receive the pulse train and has a cutoff frequency which is well below the frequency of the pulse train. The low pass filter generates a D/C voltage signal which has a voltage level that is proportional to the duty cycle of the pulse train. The D/C signal is used in a circuit that draws a current from a power supply which is proportional to the voltage level of the D/C signal. The power supply is connected to the circuit by a 4-20 mA currrent loop. 6

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Concord, OH, United States of America

Edward Bastijanic