Abstract: A data compression method and apparatus particularly suitable for use in electrical power line fault data recorders. The system performs both gain compression and frequency compression. For gain compression, a predetermined number of samples are analyzed to determine a gain setting common to each sample in the set of samples. A reduced data string consisting of a gain code and data words having fewer bits than the input words are transmitted as a compressed data string. For frequency compression, a sample set representing the input signal is decimated until there remain only a sufficient number of data samples to satisfy the Nyquist criterion for the highest frequency component of interest. The frequency compressed output data string comprises a frequency code representing the highest frequency of interest followed by the set of decimated data samples.

Abstract: A data compression method and appartus particularly suitable for use in electrical power line fault data recorders. The system performs both gain compression and frequency compression. For gain compression, a predetermined number of samples are analyzed to determine a gain setting common to each sample in the set of samples. A reduced data string consisting of a gain code and data words having fewer bits than the input words are transmitted as a compressed data string. For frequency compression, a sample set representing the input signal is decimated until there remain only a sufficient number of data samples to satisfy the Nyquist criterion for the highest frequency component of interest. Also included is a circuit for reproducing the waveform envelope. Positive and negative peak detectors provide signals representative of the peaks of the waveforms.

Abstract: An improved temperature transducer for use with a KYZ pulse data recorder. A temperature sensor provides a temperature signal proportional to ambient temperature. An integrator circuit and comparator circuit responsive to the temperature signal provides pulses at a frequency which is proportional to temperature. The pulses are provided over the standard three-wire KYZ pulse cable to the input of the data recorder. The circuit is extremely low power, highly accurate, and requires only the three-wire KYZ connection. No external power supply or cable is required, since the circuit draws its power from the pull up resistors in the KYZ data recorder input. Also disclosed are techniques for improving accuracy and minimizing power consumption in the circuit, and an improved integrator circuit.

Abstract: 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.

Abstract: A direction sensitive optical shaft encoder includes an optical shutter disk mounted to a shaft for rotation therewith, the optical shutter disk bearing at least first and second radially concentric tracks having alternating light transmissive and light blocking areas formed thereon. The light transmissive and light blocking areas of one track are angularly offset with respect to the light transmissive and light blocking areas of an adjacent track. A pair of light emitters and light detectors are disposed on opposite sides of the optical shutter disk and aligned with the first and second concentric tracks, respectively. Because the pattern of light transmissive and light blocking areas on the two tracks are angularly offset, the output of the light detectors follows a unique pattern which is dependent upon the direction of rotation of the optical shutter. The frequency of repetition of the pattern of outputs by the light detectors is indicative of the speed of rotation of the optical shutter.

Abstract: A bidirectional data communications distribution network is established between the system operations center (SOC) and customer terminals of a load management and electrical energy distribution system. The distribution network comprises independent processor controlled, primary communications interface units (PCI) in communication with the SOC over telephone lines or other medium. Each PCI is in turn in communication with a plurality of independent processor controlled, secondary communications interface units (SCI) over electrical utility primary distribution power lines. Signals between PCIs and SCIs on the primary distribution power lines are code division multiplexed using direct sequence spread spectrum (DSSS) signal processing. Each SCI continuously polls a number of assigned customer load terminals on the low voltage side of the electrical energy distribution system, storing and calculating meter register readings and load status.

Abstract: A modular meter assembly includes replaceable modules for a power supply, a register, a function controlling option circuit and a display of a measuring meter. The modules are provided with mechanical and electrical interconnectors, permitting for simplified assembly, repair, maintenance and replacement. An adaptor frame used with the meter assembly provides for retrofitting the improved modular structure on existing meters, to permit upgrading of the functions performed by the existing meters.

Abstract: A sequence of samples of a time varying signal is multiplied by respective, corresponding, multiplicands corresponding to values of a separate signal. The multiplicands are provided as ratios of capacitances switched into and out of a circuit between the input time varying voltage and an accumulating integrator. The arrangement is used to provide multiplication of a time varying signal by corresponding amplitudes of a sinusoid without requiring generation of a sinusoid. The arrangement is used for sampling, detecting signals utilizing a simulated local oscillator signal, and for generation of an arbitrary time varying function.

Abstract: A plastic scintillator comprises a polymethylpentene thermoplastic material containing a fluorescent additive. This plastic scintillator material functions at high temperatures with excellent optical properties in the detection of neutrons. The plastic scintillator may also include an energy transfer compound, a wavelength shifter, a solubility enhancer for the polymethylpentene and a decolorizing agent.

Abstract: A photomultiplier includes a solid disk dynode and a pair of annular guiding electrodes disposed about the disk dynode transversely along the central axis of the photomultiplier tube on opposite sides of the dynode. The secondary and subsequent dynodes may be of conventional (e.g. venetian blind) construction or of solid disk construction. The solid disk dynode and guiding structure exhibits improved photoelectron pulse-height resolution and a better signal-to-noise ratio than a conventional venetian blind type dynode. In addition, the solid dynode structure is less susceptible to physical shock than conventional photomultiplier dynode designs.

Abstract: A Hall device is formed from a generally rectangular body of material exhibiting the Hall effect, with two excitation electrodes disposed along opposite edges of the device. Two Hall output voltage electrodes are disposed along one of the remaining edges of the main body and at least one additional output electrode is disposed on the edge of the main body opposite the first pair of electrodes. At least two of the output electrodes are offset from a centerline drawn through the electrical midpoint of the main body. By deliberately offsetting the Hall voltage output electrodes from the centerline the first and second order voltage offsets due to inhomogeneities of the Hall material and mask misalignment are eliminated or easily compensated.

Abstract: A solid state electricity demand recorder (10) is controlled by a programmable microprocessor (38) to obtain energy demand survey and billing data. The accumulated count of pulses during a record interval is compared with an encoded register reading obtained from an electricity meter (30) at the end of the record. If there is acceptable correlation between the accumulated count and encoded meter reading, the interval pulse counts associated with that record are deemed verified. The recorder is programmably configurable for operation over a wide range of customer demand by scaling the KYZ pulse input frequency.

Abstract: A solid state electricity demand recorder (10) is controlled by a programmable microprocessor (38) to obtain energy demand survey and billing data. The accumulated count of pulses during a record interval is compared with an encoded register reading obtained from an electricity meter (30) at the end of the record. If there is acceptable correlation between the accumulated count and encoded meter reading, the interval pulse counts associated with that record are deemed verified. The recorder then downloads the recorded demand data to a central computer at a preselected time over a communications line. The recorder is receptive to communications and commands from the central computer at times other than the normal preprogrammed data downloading time by detecting a particular number of rings.

Abstract: A solid state electricity demand recorder (10) is controlled by a programmable microprocessor (38) to obtain energy demand survey and billing data. The accumulated count of pulses during a record interval is compared with an encoded register reading obtained from an electricity meter (30) at the end of the reord. If there is acceptable correlation between the accumulated count and encoded meter reading, the interval pulse counts associated with that record are deemed verified. Power for the recorder (10) is obtained from the power line, except during power outages in which case a battery (28) provides back-up power. Error conditions such as power outages, meter failure, and low battery condition are automatically detected and communicated to the central computer for remedial action by the electrical utility.

Abstract: A charge balance voltage-to-frequency converter utilizes CMOS circuitry to provide a digital pulse output proportional to an analog input signal. The converter approaches a desired charge balance by cycling between a charging and a discharging state. A clock signal provided by a stable oscillator is applied to a clock input of a CMOS D-type flip-flop. The analog input signal effectively is fed to a non-inverting input of an integrating amplifier. The output of the integrating amplifier is fed to the D input of the flip-flop, which input has a threshold level. The Q output of the flip-flop is connected via a voltage divider to an inverting input of the integrating amplifier. This configuration eliminates the need for a dual polarity power supply. When the output of the integrating amplifier rises above the threshold level of the D input, on the next rising edge of the clock signal, the flip-flop sends feedback pulses to the inverting input, thus beginning the discharge state.

Abstract: In a solid state electricity meter, a display consisting of a number of juxtaposed display elements provides, in a vector form, an indication of the direction and range of power flow in the line being measured. Circuitry for driving the vector display comprises a first memory storing a plurality of power measurement references and a second memory storing corresponding vector symbols. A microprocessor compares each power measurement with the reference stored in the first memory to determine the range of power measurement and, in response, reads the corresponding vector symbol from the second memory to drive the display.

Abstract: A solid state electricity demand recorder (10) is controlled by a programmable microprocessor (38) to obtain energy demand survey and billing data. The accumulated count of pulses during a record interval is compared with an encoded register reading obtained from an electricity meter (30) at the end of the record. If there is acceptable correlation between the accumulated count and encoded meter reading, the interval pulse counts associated with that record are deemed verified. Power for the recorder (10) is obtained from the power line, except during power outages in which case a battery (28) provides back-up power. The time of day and date of detection of a low battery condition is stored and used to assess data reliability.

Abstract: A method of initializing the position of an optical shaft encoder without having to precisely index the encoder with respect to its shaft. The optical encoder includes an optical shutter mounted for rotation with the shaft and light emitters and light detectors associated with the optical shutter for respectively illuminating and detecting a predetermined pattern of code markings formed on the optical shutter. An electrical circuit, such as a suitably programmed microprocessor, is responsive to the status of the light emitters and light detectors for determining the angular position of the optical shutter and shaft relative to the light emitters and detectors from the detected predetermined pattern. The optical shutter is mounted to the shaft in some arbitrary position and the code pattern associated with this position is detected by the electrical circuit.