Schlumberger Industries

Sangamo Weston, Inc.

Grt, Inc.

R Wendell Goodwin

David Nelson Makinson

Charles W Roberts

John F Rilling

Richard C Timko

George H Stephens

Arnaud De Montgolfier

Jean Babaud

An improved laminated ferromagnetic FIG. 8 power meter core is provided. The core is fabricated from a plurality of ferromagnetic plates and is formed in the general shape of a FIG. 8. The central leg of the core has a cross-sectional area that is larger than the cross-sectional area of other parts of the core. The core gap, in which a Hall-effect sensor is located, has gap faces with chamfered or rounded over edges to reduce fringing and bypassing effects. The core is formed without discontinuous corners that can result in local saturation and, in use, accommodates electrical power conductors in an over-under looping relationship through the openings of the core to provide a more homogeneous magnetic flux within the core and thus more reliable metering. The overall result is a core with a higher saturation point and thus a wider dynamic range than prior art cores.

Laminated figure 8 power meter core

An electricity meter and method for measuring VA power consumption. The electricity meter comprises a transducer circuit receiving line current and line voltage and producing a first signal corresponding to active power on the line, and a level shifting circuit responsive to the first signal for producing a second signal corresponding to apparent power.

Electricity meter and method for measuring apparent power

An air-coupled current transformer is provided with a primary current conductor and two secondary coils connected such that the emf induced in each coil by an external disturbing magnetic flux is subtractive, whereas the emf induced by the current in the primary is additive. Two ferromagnetic core pieces enhance the rejection of the emf induced by the disturbing flux. Ceramic spacers are inserted into air gaps between the core pieces for maintaining the gaps fixed to keep the scale factor of the transformer independent of temperature.

Unshielded air-coupled current transformer

An emulator which is able to operate on a standard single phase 120 VAC line, generates simulated three-phase alternating current in order to demonstrate the operation of a polyphase electricity meter. The emulator is also capable of demonstrating the operation of the polyphase electricity meter which has been incorrectly wired into the polyphase circuit, i.e., with incorrect or missing connections to the current transformers; or in which there are problems with the phasing of the polyphase circuit, i.e., incorrect phase differences between circuits or between the currents and voltages within any of the phases.

Polyphase emulator for single phase circuit

An optical sensor for monitoring position of a movable object comprising a LED and a phototransistor is provided with control circuitry, which is responsive to an output signal generated by the phototransistor for causing the LED to suspend radiation of light. When the light reflected from a reflective area of the object falls on the phototransistor, the control circuitry turns off the LED as soon as the output of the phototransistor goes below a threshold level signifying that the phototransistor has been turned on. When the light is absorbed by a non-reflective area of the object and the phototransistor is not turned on, the control circuitry turns off the LED after a predetermined time period, which is chosen to be slightly larger than the response time of the phototransistor.

Optical sensor control including the suspension of light radiation

A differential electrical current shunt which is particularly adapted for the measurement of large currents with high accuracy and substantially free of errors due to ageing, connection resistance and differentials therein and thermally induced resistance changes. The shunt, according to the invention divides the large current into two substantially equal portions by forming a preferably elongated aperture in a conductor carrying the large current; the two portions of the conductor formed by the aperture having substantially equal but slightly differing resistances. The two conductor portions are formed with respect to a core such that the conductor portions each form a single turn coil on the core with the induced flux from each conductor portion opposing that included in the coil by the other of the two conductor portions. Since the conductor portions are in close proximity and formed of a unitary conductor and good thermal and electrical conductivity is assured at both ends of the unitary conductor, proportionality of resistance of the conductor portions is accurately maintained throughout a wide range of currents, resistive heating and other environmental conditions.

Differential current shunt

An apparatus for indicating the peak tangential velocity of a swung sporting goods implement such as a tennis racquet, golf club, or baseball bat, comprises a tube having a longitudinal bore. A seismic mass is slideably disposed within the bore of the tube, and a spring operates to pull the seismic mass toward the proximal end of the tube. A reset mass is normally captured at the distal end of the tube but is selectively released to slide within the bore of the tube. A peak velocity indicator is slideably disposed within the bore of the tube between the seismic mass and the reset mass, the peak velocity indicator frictionally engaging the inner walls of the tube such that it is displaceable longitudinally within the bore of the tube by an applied force but maintains its position within the bore of the tube once the applied force is removed. When the apparatus is affixed to the club or racquet with the longitudinal bore aligned with the shaft of the implement, swinging the implement generates a centrifugal force which displaces the seismic mass. The displaced seismic mass pushes the peak velocity indicator ahead of it, and the peak velocity indicator remains lodged in its forwardmost position of displacement at the completion of the swing. After the position of the peak velocity indicator is observed, the rest mass is released from its position at the distal end of the tube and slides down the tube to return the peak velocity indicator to its ready position.

Swing velocity indicator

DC magnetic flux bias imposed on a magnetic core of a current transformer is compensated in response to an indication of the amplitude and duration of opposite polarity secondary winding current components. In a second embodiment, the magnetic bias is compensated by responding to the integral of the secondary current. The integral of the secondary current is a measure of the magnetic core flux variations. The durations of the positive and negative flux variations are compared.

Current measuring and magnetic core compensating apparatus and method

Tampering with an optically encoded meter display register or metering mechanism can be readily detected by comparing the quantity shown by the meter display with the encoded values of the optical encoders. A discrepancy is indicative of tampering with the register display. Any tampering with the optical encoders or the metering mechanism can be detected by comparing the present position of the encoders with that of a previous position and generating a signal indicative of tampering when these positions have a predetermined relationship to each other.

Method and apparatus for detecting tampering with a meter having an

An optical shaft encoder includes an optical shutter mounted to a shaft, the shutter bearing light transmissive and light reflective areas, at least a first light emitter and a first light detector arranged adjacent one another on one side of the optical shutter, and at least a second light emitter and a second light detector arranged adjacent one another on a second side of the optical shutter and opposite the first light emitter and first light detector. The optical shutter comprises a disk or drum having the reflective and transmissive areas arranged in a predetermined pattern on its surface. The light emitters are alternately energized and the outputs of the two light detectors, which are dependent on the arrangement of reflective and transmissive areas of the optical shutter, are then detected and compared with a predetermined pattern of such outputs representative of the various angular positions the optical shutter and shaft can take. With this arrangement up to 16 different output states are possible. This enables the optical shutter to resolve 1/16 of a revolution of its associated shaft which is more than adequate for detecting the shaft position of a clock-dial type register display of a gas, water or electric meter.

Optical shaft encoder

The disclosure is directed to an apparatus and method for generating noise having characteristics of repeatability and reproducibility. A pseudo-random bit generator is responsive to clock pulses for simultaneously generating, at each clock pulse, a plurality of parallel pseudo-random digital bits which are successive bits of a pseudo-random sequence. In particular each new plurality of parallel bits is a successive group from the same pseudo-random sequence, thereby insuring a maximum number of totally uncorrelated groups. The bits generated at each clock pulse are operated on to produce an output noise signal as a function of the plurality of pseudo-random parallel bits generated at that clock pulse. In an embodiment of the invention, the operation on the plurality of bits comprises summing the value of the bits to produce a noise signal, the noise signal exhibiting a substantially Gaussian distribution with time. In another embodiment of the invention, the operation on the plurality of bits comprises comparing a first group of the plurality of bits to a second group of the plurality of bits and generating an output signal, at each clock pulse, as a function of the comparison. The output signal thereby occurs at substantially random intervals and constitutes a substantially random distributed noise signal.

Apparatus and method for digital noise synthesis

The disclosure is directed to an improved apparatus and method for generating a specified statistical distribution. Digital bits having properties of randomness are produced. In response to a group of the digital bits, a signal is generated which approximates the specified statistical distribution. When a particular characteristic of a group of digital bits is sensed, the generated signal is modified so as to obtain a statistical distribution that more closely approaches the specified statistical distribution.

Growing community of inventors

Dunwoody, GA, United States of America

R Wendell Goodwin