Abstract: A protective relay of the type consisting of a relay contacts controlled by means of a relay coil further includes a pair of triacs controlled by an optical switch. The high speed response is attributed to the configuration of the triacs while high ampere rating is provided by the contacts.

Abstract: An arcing fault detection module (4) for detecting arcing faults in an electrical current distribution circuit (8) comprises a filter circuit (9) and an autocorrelation circuit (10). The filter circuit (9) is electrically connected to the distribution circuit (8) and samples current with the distribution circuit. The filter circuit (9) includes a band pass filter (12) to filter out fundamental and high frequency components from the sampled current, and a comparator (13) to convert the sampled current to a digital signal. The autocorrelation circuit (10) receives the digital signal from the filter circuit (9). The autocorrelation circuit (10) includes a plurality of shift registers (15-18) for storing the digital signal for a predetermined sample period, and a plurality of EXCLUSIVE-OR gates (35-37,41, 43, 44) and OR gates (38, 39) to detect odd and even harmonic signals.

Abstract: A control circuit for distributed electrical equipment includes a relaxation oscillator configured for voltage to frequency conversion whereby the output frequency is proportional to the input voltage signal. An opto-coupler provides voltage isolation to the circuit and a standard 8-bit counter translates the frequency signals to a low voltage count data.

Abstract: An integrated protection unit is a circuit breaker which includes basic overcurrent protection facility along with selective electrical accessories. A molded plastic accessory access cover secured to the integrated protection unit cover protects the accessory components contained within the integrated protection unit cover from the environment. A combined overcurrent trip actuator and accessory unit is either field-installed or factory-installed within the integrated protection unit. One such actuator-accessory responds to a process current loop signal upon command to interrupt circuit current to associated electrical equipment.

Abstract: A protection circuit for three-phase power systems incorporates overcurrent protection along with phase loss and phase imbalance by means of common current sensing transformers. The phase loss and phase imbalance are determined by a pairwise comparison algorithm.

Abstract: An ampoule sealing apparatus has a pivotable arm for moving an unsealed ampoule from a first position to a second position, a horseshoe-shaped burner defining an interior area in which the ampoule neck is received at the second position. A vibrator attached to the mechanical arm in order to help induce the evacuation of air from the ampoule. A vacuum source, optionally associated with a purge gas source, is associated with the mechanical arm in order to evacuate air from the ampoule and a thermocouple controller monitors the lighting of the burner and shuts off the flow of fuel thereto if the burner is not lit or if the flame is extinguished within a predetermined period of time.

Abstract: A digital circuit interrupter includes a microprocessor programmed for tailored overcurrent protection to industrial power systems containing a plurality of electric motors as well as motor protective relays. A communication link permits the overcurrent set points to be selectively set within the microprocessor memory from a remote location. The tailored overcurrent motor trip parameters are then derived by means of a logarithmic interpolation algorithm which resides in the microprocessor memory.

Abstract: A digital circuit interrupter includes a microprocessor programmed for tailored overcurrent protection to power systems. A communication link permits the over-current set points to be selectively set within the microprocessor memory from a remote location. The over-current trip parameters are then derived by an algorithm which resides in the microprocessor memory.

Abstract: A circuit breaker warning and control relay provides visual indication of an impending overcurrent condition. Sufficient time is thereby allotted for manual intervention to prevent damage to material and equipment utilized within sensitive manufacturing processes. The relay can be arranged to automatically shut-down selected equipment in a predetermined order for load-shedding implementation.

Abstract: The root mean square value of sensed current within a protected circuit is calculated. A frequency multiplying circuit produces a pulse stream having a frequency proportional to the square of the amplitude of an analog signal representation of the circuit current. A root mean square value over a prescribed interval is developed from the squared current value.

Abstract: A molded case circuit breaker provides both overcurrent protection as well as accessory protection function by means of a self-contained electronic trip actuator module. Undervoltage release function is provided by a separate undervoltage release assembly that includes the undervoltage coil and an electronic control circuit. Shunt trip facility is provided by the shunt trip coil and a shunt trip control circuitry. The overcurrent, shunt trip and undervoltage release coils are arranged on a magnetic circuit within the electronic actuator module.

Abstract: An electronic overcurrent circuit interrupter utilizes a digital processor for performing RMS sampling of circuit current for comparison to stored long time and short time current values and time delays before tripping the breaker. A magnetic core current transformer is employed for providing an output current signal to the digital processor. Upon detecting core saturation, which occurs at high currents, an analog detection circuit interrupts the RMS sampling and causes the digital processor to time out the shortest pre-selected time delay before tripping the breaker.

Abstract: Circuit protection and protective relay functions are provided by common circuit elements under the control of a single processor unit. Voltage and current values are obtained on a continuous basis and these values are continuously monitored within the processor to determine the electrical status of a protected power distribution system. Upon the occurrence of an overcurrent or undervoltage condition, the circuit is interrupted by operation of a circuit breaker trip solenoid causing the breaker contacts to open. When the overcurrent or undervoltage condition ceases to exist, the circuit breaker contacts could be closed by operation of a controlled relay. The ROM and RAM storage elements within the processor unit are continuously tested and the circuit breaker contacts are opened upon indication that the ROM or RAM element is nonfunctional.

Abstract: The root mean square value of sensed current within a protected circuit is used to determine the occurrence of an overcurrent condition. A frequency multiplying circuit produces a pulse stream having a frequency proportional to the square of the amplitude of an analog signal representation of the circuit current. A root mean square value over a prescribed interval is developed from the squared current value. The RMS value is processed within an integrated circuit trip unit to determine an overcurrent condition and to operate a pair of separable contacts to interrupt the circuit current.

Abstract: Digital implementation of the overcurrent determination and time delay before tripping in a static circuit breaker trip unit allows the trip unit circuit to be manufactured in a single chip configuration. The signal after A/D conversion is compared within a magnitude comparator to determine pickup. A pulse stream proportional to the square of the overcurrent signal is developed by multiplying the outputs of two magnitude comparators which compare the A/D level with a continuous binary count. The time delay determination is obtained by means of 3 cascade connected divide by two counters with their outputs connected to a data selector, or by a rate-limiter circuit which uses a fixed frequency to gate a pulse stream proportional to the overcurrent level squared.

Abstract: An analog signal processor used within a static trip unit is provided with an A/D converter, a digital processor and an electrically alterable non-volatile memory (EAROM) for providing trimming and calibration facility to the trip unit. The EAROM provides the ability to store parameters calculated by the user during the manufacturing process of the trip unit. Key measured or environmental variables are created and a correction algorithm is generated and stored along with data. The trip unit is then capable of self-calibration by applying the correction factor to compensate for variations in the component sensitivity. In one application, the current sensing transformer is precalibrated and provided with a correction factor and a correction algorithm. In another application, the thick film resistors within the long term trip mode network, the short term trip mode network and the power supply voltage regulator are "trimmed" by means of stored correction values.

Abstract: A transparent transceiver interface between a broadband power line communication system and a baseband data processor includes an autocorrelation receiver. The autocorrelation receiver achieves an extremely narrow bandpass function without passive elements. The receiver accepts wideband limited signals from the power line and performs an autocorrelation test over a single cycle of the carrier frequency.

Abstract: A digital controller for a converter comprises a memory for storing digital representations of the switching patterns for operating the converter to produce a predetermined segment of each one of a plurality of waveforms, respectively, the memory being operable for repetitively outputting at least a selected one, or concurrently one per phase, of the switching patterns, the waveforms being divided into equal angled zones, a respective predetermined segment when oriented in phase and made of appropriate polarity, substantially approximating the portion of its associated waveform within any of the zones of this waveform; and a decoder receptive of the switching patterns from the memory, for selectively gating the digital signals thereof onto a plurality of control lines, in an iterative manner, for operating the converter to produce a desired waveform or polyphase related waveforms, with the segments of each zone thereof properly oriented in phase and polarity.

Abstract: A coaxial electric power transmission cable has an inner conductor within an outer conductor with solid dielectric material provided in the space therebetween. The dielectric material is solid at operating temperatures but non-solid at ambient temperature. An insulative spacer is provided for maintaining the coaxial alignment. The spacer includes insulative material which is identical to the solid dielectric material and may include a solid insulative insert having a solidification point higher than the insulative material whereby at least approximate coaxial spacing may be maintained should the insulative material not be maintained as a solid.

Abstract: There is disclosed an improved pile point for foundation piles such as the H-beam pile. The point provides an improved biting edge which eliminates skidding and slipping on inclined rock stratum or when the pile is used as a batter pile. The point includes a web and a pair of flanges positioned at the ends of the web and perpendicular thereto, the flanges including, typically, angled side portions to which are fixedly secured teeth-like protrusions. The latter provide a biting edge which grab hold of the supporting stratum, even when it is at a sharply inclined angle, to eliminate slipping and skidding on such surfaces.Such teeth-like protrusions are provided on a flattened portion of the web and flange affording additional biting edges.The latter protrusions can be arranged such that the point can provide improved biting regardless of its orientation relative to the rock stratum.