Abstract: A circuit breaker suitable for use on both AC and DC circuits includes a magnetically permeable core surrounding a current carrying conductor of the circuit breaker. A bimetal member is thermally coupled to the core such that induction heating of the core due to overload AC current flowing through the conductor is operative to deflect the bimetal and actuate a trip device. The circuit breaker also includes a pair of braided copper shunts connected between the conductor and the bimetal such that resistive heating of the conductor due to overload DC current flow through the breaker will cause the bimetal to deflect and actuate a trip device. The bimetal is mechanically isolated from the conductor such that relative movement therebetween will not affect thermal calibration of the circuit breaker.

Abstract: A one-piece, molded, terminal cover providing a weatherproof enclosure externally of a field-mounted component is disclosed. A first member has a back face adapted for external connection to the field-mounted component. The back face has at least one opening communicating with an opening in the field-mounted component through which outgoing wires extend. The back face further has a continuous, external rib around the opening for providing a gasket. The first member additionally has a top face, a bottom face and two side faces. A second member has a front face, a top face, a bottom face and two side faces. The bottom face has at least one opening through which incoming wires extend. The first and second members are flexibly hinged and cooperate when in the closed position to define the weatherproof enclosure wherein the incoming and outgoing wires are connectable. Means are provided for locking the first and second members in the closed position.

Abstract: An electric energy meter includes a mutual inductance current transducer formed by primary winding means for direct connection to the current component of an electric energy quantity to be measured. Secondary winding means is inductively coupled to the primary winding means to produce an analog signal that is proportional to the time derivative of the current component. The current responsive analog signal and a voltage responsive analog signal are both applied to an electronic watthour measuring circuit.

Abstract: An earplug for use by an underwater diver includes a tubular vessel of soft flexible material adapted for insertion into the auditory meatus, a plurality of sealing rings surrounding the vessel to seat against the interior surface of the auditory meatus to provide a watertight seal, and a flexible inner vessel end inwardly rolled back upon itself to define a variable volume between the inner end, the interior surface of the auditory meatus, and the eardrum. The variable volume expands and contracts as the diver ascends or descends to maintain pressure equalization across the eardrum, yet prevent the entry of water into the auditory meatus. If the eardrum should rupture, the inner end of the vessel flexes to its full extent but still prevents the entry of water into the middle and inner ear regions.

Abstract: A load management terminal is utilized as an end device in a utility's distribution network communication system. The distribution network carries electrical power as well as communication signals. The load management terminal is comprised of a power line coupling unit for connecting the load management terminal to the power distribution network. A signal receiver and conditioning unit produces a command signal in response to a received communication signal. A solid state memory contains preprogrammed instructions and data. A control logic circuit performs load control functions in response to the preprogrammed instructions, data and the command signal. These load control functions include the opening and closing of load control switches for selectively disconnecting and connecting, respectively, customer loads. A cold load pick-up produces power outage information enabling the load management terminal to provide local, load control functions.

Abstract: A solid-state event-logging system records the occurrence of specified events in a removable, solid-state, memory cartridge. Counters continuously count pulses produced by a plurality of electrical energy measuring devices. Sample values of the continuous counts are produced and input to a microprocessor wherein each sample value has the previous sample value subtracted therefrom. The difference is added to an interval sum stored in a random access memory. The interval sums, together with real time information produced by a clock, are input to the memory cartridge according to a predetermined format. The clock is maintained in synchronization with the frequency of the line voltage by the microprocessor.

Abstract: An automatic control transfer device for selectively energizing an electrical distribution system from a pair of electrical power sources. The device includes means for sensing electrical conditions on both of the sources and programmable electronic digital logic to selectively energize associated circuit interrupters for switching a distribution system between the two sources. A plurality of time delay functions are provided utilizing a separate oscillator for each function, each oscillator providing input to a common digital counter. The device senses the status of associated circuit interrupters to provide interlocking and lockout functions as well as proper switching commands for either two- or three-circuit interrupter systems. Means are also provided for testing the entire device without initiating an actual source transfer.

Abstract: A remote device for receiving communication signals carried by the phase conductors of a multi-phase power distribution network communication system is dislosed. The remote device includes a circuit for independently receiving each of the communication signals carried by the phase conductors. The receiving circuit produces an input signal having a serial format in response to each of the received communication signals. A clock circuit produces a train of clock pulses and a train of strobe pulses, each of the strobe pulses being produced in response to the production of a predetermined number of clock pulses. A serial-to-parallel shift register is responsive to each of the input signals. At the positive transition of each of the clock pulses, a sample value of each input signal is clocked into one of the serial-to-parallel shift register. Upon the production of each strobe pulse, the samples are transferred from each shift register to a latched storage register.

Abstract: Isolated phase bus duct includes apparatus for adjustably attaching an insulator to the inner surface of a disconnecting switch enclosure to accommodate positional and angular tolerances. The apparatus includes a base member tangential to the surface of the enclosure having a first circular aperture with angled sidewalls. A first circular positioning plate having an angled outer sidewall is seated in the first aperture and includes a second circular aperture non-concentric with the first plate. The second aperture also includes angled side walls and has mounted therein a second circular positioning plate. The second plate has a third circular aperture therein which has angled sidewalls and is non-concentric with the second plate. Seated in the third aperture is a ball plate adapted to be bolted to an insulator.

Abstract: An apparatus and method for coherent phase demodulation of a binary phase shift keyed carrier includes sequentially processing plus and minus polarity samples of plural carrier segments occurring within each carrier data symbol. The samples for each segment provide a binary coded signal for producing corresponding first and second relative phase angle vector signals. The second vector signals are summed over several data symbols to generate reference phase angle signal vector signals. Correlation signals are produced from phase comparison of each of the first vectors with the reference vector signals. The correlation signals are summed in a synchronized relationship for the carrier segments included in each data symbol. The sums of the correlation signals represent either positive or negative correlations with the one and zero data bits of the carrier data symbols.

Abstract: A circuit interrupter includes a microcomputer controlled trip unit having a front panel numeric display and a plurality of LED displays for providing post tripping indication of cause-of-trip and trip current value. Reliable operation is provided during power up conditions. Means are also provided for accurate performance of long delay and ground fault tripping operation.

Abstract: A circuit interrupter includes a circuit breaker mechanism having a trip coil energized by a current transformer to separate the contacts upon command of a microcomputer-based trip unit during overcurrent conditions. A bimetallic normally-open thermal switch is mounted on the internal conductors of the breaker and is connected in parallel with the trip unit to energize the trip coil when the conductors overheat. The thermal switch is also connected to the interrupt terminal of the microcomputer to cause appropriate display and alarm information upon activation of the thermal switch.

Abstract: An encoder includes an array of variable resistance photosensors responsive to variations of incident illumination. The array is interconnected in a row and column matrix having row inputs connected to a sampling control device for sequential application of a predetermined voltage to the inputs. The matrix column outputs are connected to a detecting circuit having a current-measuring detector for receiving sensing currents from the outputs and for producing current responsive detection signals in response to the application of the predetermined voltage at the inputs. The outputs are held at a constant voltage, thereby providing effective isolation between the column outputs and eliminating interaction between elements connected to adjacent columns without the need of additional isolation means, such as isolation diodes, at each matrix intersection.

Abstract: A detachable enclosure unit for use at standard watthour meter sockets includes a central housing for carrying auxiliary equipment and an integral mounting extension with a snap-on retainer for adaptive mounting to both ring and ringless sockets. The retainer provides a removable circumferentially disposed flange surface equally accommodating the different types of meter sockets.

Abstract: A mutual inductance current transducer includes a primary winding for direct connection to the current component of an electric energy quantity to be measured by an AC energy meter. A secondary winding is inductively coupled to the primary winding to produce an output signal that is proportional to the time derivative of the current component. The output circuit provides a current responsive input to an energy measuring circuit also receiving a voltage responsive input.

Abstract: An input module and a sample and hold circuit cooperate to produce sample values representative of the instantaneous magnitudes of three-phase line voltages and line currents delivered to a load by a power distribution system. The sample values representative of the line voltages are input directly to a multiplexer. The sample values representative of the line currents are input to the multiplexer both directly and through ranging amplifiers. When the sample values of the line currents are below a predetermined magnitude, the sample values amplified by the ranging amplifiers are used, thus increasing the accuracy of the metering system. The sample values are input to an analog-to-digital converter where the sample values are digitized. A control circuit calculates a plurality of indica of the AC electric energy quantity delivered to the load from the digitized data. An output module is responsive to the control circuit for displaying, recording or transmitting the calculated indica.

Abstract: A register is coupled to a rotor which is driven in stepped rotation by magnetic fluxes directed through electromagnetic pole pieces of a stator. The pole pieces carry coil windings which produce the magnetic fluxes by being sequentially and discretely energized by a circuit responsive to pulse signals, each pulse signal representing a quantum of a quantity to be measured.

Abstract: A multirate dial register for meters having a rotatable measuring element includes plural sets of dial indicators having at least one set thereof selectively coupled by a clutch mechanism to the measuring element such that the ratio of measuring indications at the one set of dial indicators is controllable at the front of the register for converting between measurements of different parameters of a measured quantity by a solenoid actuated clutch wherein one solenoid plunger end controls the clutch and the opposite plunger end controls an on-off dial indicator.

Abstract: A clutch mechanism for time of day watthour meter dial registers includes a clutch mechanism having a driving part continuous driven by a rotating measuring element so that it is freely rotatable when the clutch is open and a clutch driven part which is shiftable between clutch open and clutch closed positions by a lever arm which further arrests rotation of the clutch driving part during the clutch open position.

Abstract: A communication system for a three-phase power distribution network is comprised of a plurality of remote devices, with certain of the remote devices being used as signal repeaters. Injection point circuitry provides an out-going communication signal which is coupled to the three-phase conductors such that each phase conductor carries an identical, independent, outgoing communication signal. The signal repeaters are each coupled to at least two of the three-phase conductors. Each signal repeater includes circuitry for producing a composite signal in response to the coupled signals. The composite signal has a signal-to-noise ratio typically superior to, but not worse than, the signal-to-noise ratio of the best of the coupled signals. The remainder of the remote devices are independently coupled to at least one of the three-phase conductors so as to facilitate communication with each of the remote devices.