Abstract: A method for monitoring temperature or pressure by the steps of: providing a light path (30-42) having a light attenuating characteristic which is substantially independent of light wavelength, at least with respect to a given wavelength range; conducting light having different first and second wavelengths which are in the given wavelength range along the light path (30-42); controlling the intensity of the radiation along the light path (30-42) as a function of the temperature or pressure to be monitored and the light wavelength; producing (76-82): four signals having values representing the light intensity at, respectively: the output end of the path for light having the first wavelength; the input end of the path for light having the first wavelength; the output end of the path for light having the second wavelength; and the input end of the path for light having the second wavelength; and deriving (86-90) an output signal having a value representing the ratio of the mathematical product of the values of t

Abstract: An electronic watt-hour meter includes a multiplier/integrator circuit which performs "pulse height-pulse width" multiplication of current and voltage and simultaneously integrates the product of this multiplication to generate packets of electrical charge representative of the electrical energy consumed. A first set of switches alternately, at one-half the frequency of a pulse width modulated (PWM) signal having a duty cycle proportional to the current, connects one of a pair of capacitors to be charged by the voltage signal, and the other capacitor to dump charge into an accumulator. When charge in the accumulator reaches a preset value, a pulse is generated representing a predetermined unit of energy. When the first capacitor is connected to the voltage signal by the first set of switches, a second set of switches applies the voltage to the first capacitor in one sense when the PWM signal has one value and in the opposite sense when the PWM signal has a second value.

Abstract: The voltage between two objects is measured utilizing an electro-optic crystal exhibiting birefringence in two axes (slow and fast) mutually orthogonal to an optic axis extending between the two objects. Two collimated light beams polarized at an angle to the slow and fast axes is passed through the crystal parallel to the optic axis with one of the collimated light beams retarded relative to the other by about 1/4 wave. The two beams emerging from the crystal are passed through a polarizer and converted to phase shifted electrical signals by photo diodes in electric circuits which regulate the sources of the light beams to maintain the peak magnitudes of the two electric signals constant and equal.

Abstract: A circuit assembly composed of: a one-piece molded support member (8); a first circuit device (32) positioned on the support member (8) and having a row of first contact elements (34) formed to have contact surfaces all lying in a first common plane; a second circuit device (36) having a row of second contact elements (38) formed to have contact surfaces all lying in a second common plane, the second circuit device (36) being secured to, and positioned by, the support member (8) such that the contact surfaces of the second contact elements (38) face the contact surfaces of the first contact elements (34), each first contact element (34) is aligned with a respective second contact element (38), and the first and second common planes are parallel to one another and are spaced a predetermined distance apart; and an elastomeric connector (10) interposed and compressed between the first and second circuit devices (32,36) for conductively connecting each first contact element (34) to the respective second contact e

Abstract: A circuit breaker having a fixed current contact (12,14), a movable current contact (16,18), a mechanism (20,22,54,66,68) for displacing the movable current contact (16,18) between a circuit closing position and a circuit opening position, and a latching member (32,34) disposed to cooperate with the mechanism (20,22,54,66,68) and movable in response to the magnitude of current flowing through the circuit to be controlled in order to cause the mechanism (20,22,54,66,68) to move the movable contact (16,18) in a manner to open the circuit when the magnitude of current flow exceeds a certain value, movement of the latching member (32,34) being controlled by a memory metal element (40,42) which is mechanically connected to the latching member (32,34) and electrically connected in the circuit to be heated by current flowing through the circuit to cause the latching member (32,34) to release the mechanism (20,22,54,66,68) when the current flowing through the circuit exceeds a given value for a selected period of tim

Abstract: An electrical transformer assembly characterized by a tank having opposite sides and a top access opening with a transformer structure movable into and out of the tank through the opening, the transformer structure including a coil and core assembly mounted within a support frame which frame has a top surface on which transformer components are mounted whereby the assembly of the transformer structure and transformer components are movable into or from the tank intact.

Abstract: The multiplexer in a multichannel, secure digital communication system repetitively embeds a sequence of byte length uniquely coded synchronizing signals in each of n successive frames of one channel of a multichannel, time multiplexed digital bit stream. Redundant protective relay data and associated parity check data are embedded in four of the n frames in a second, preferably adjacent channel, with the remaining of the n frames in the second channel containing additional of the uniquely coded synchronizing signals. The time multiplexed serial bit stream is transmitted to a remote station, preferably by fiber optic communications media. The most recent bits of the received serial bit stream equal in number to the number of bits spanned by the two channels in n frames are retained in n-1 serially connected serial in, serial out shift registers. Sixteen bit portions, a frame apart, of the retained most recent bits of the serial bit stream are applied to n serial in, parallel out shift registers.

Abstract: An AC electric energy meter is coupled to a source of AC electrical energy and to an AC load. A sensing circuit senses the amount of AC electric energy consumed by the AC electric load. An AC electric energy measuring circuit generates a pulse signal representative of the amount of AC electric energy consumed by the AC electric load. A switching circuit receives the pulse signal from the AC electrical energy measuring circuit and controls current flow from the AC electrical energy source to a stepper motor to drive an output shaft of the stepper motor in a unidirectional manner based on the pulse signal. A register is coupled to the output shaft of the stepper motor for registering the amount of electrical energy consumed by the AC electric load based on the amount of rotation of the output shaft of the stepper motor.

Abstract: A directional comparison relaying system includes forward looking pilot relays at each terminal of a protected line segment and monitors which detect predetermined incremental changes in line currents and voltages indicative of a fault. These predetermined incremental changes in current or voltages, which can be detected before the pilot relays respond, generate local blocking signals which are transmitted to the other terminal as remote blocking signals over a two-way communications channel. Trip signals for tripping circuit breakers at the associated terminals are generated from forward fault signals produced by the pilot relays but are blocked by the presence of either a local or remote blocking signal. However, the forward fault signal cancels the local blocking signal and the corresponding remote blocking signal at the other terminal so that when both pilot relays see an internal fault, the circuit breakers at the two terminals are tripped simultaneously.

Abstract: Coil-core assembly for a transformer including a plurality of coils and cores supported in a U-frame. The frame includes a cross member from whose ends legs extend. The cross member and the legs are channels. Near the corners of the frame the flanges of the channels are separated so that the legs are, in effect, hinged about the material remaining at the corners. Before the coils and cores are inserted in the frame, the legs are set at an angle of between 91.degree. and 93.degree. to the cross member so that the coils and cores may be readily positioned in the frame. On each side of each gap, spanning the gap, axially coextensive lugs are welded to the flanges. The coils and cores are disposed on the cross member between the legs.

Abstract: Apparatus for coupling a high voltage power distribution system (2) to a communications device (14), the system (2) carrying electrical energy in the form of a high voltage at a power frequency and communications signals at a frequency higher than the power frequency, composed of:a capacitive power factor adjustment unit (4) connected to the distribution system (2) to correct for baseline loading and inherent reactance of the distribution system (2);a blocking unit (6) connected between the adjustment unit (4) and ground, the blocking unit (6) having an impedance which varies directly with frequency such that the voltage across the blocking unit (6) at the power frequency has a value substantially less than the high voltage at the distribution system (2) and the communications signal voltage across the blocking unit (6) has a value only slightly less than at the distribution system; anda signal coupling unit (10,12) having a low impedance at the communications signal frequency and connected between the blocki

Abstract: A predetermined unsymmetry of a bipolar waveform is detected by apparatus which includes a circuit which generates a pulse for each zero crossing of the waveform. Each zero crossing pulse triggers a first retriggerable one-shot for a first interval T.sub.1. Timing out of the first one-shot triggers a second retriggerable one-shot for a second interval T.sub.2. If both the first and second one-shots have timed out a third one-shot is triggered for a third interval T.sub.3. The intervals are selected such that twice T.sub.1 plus T.sub.2 is equal to the period of one cycle of the bipolar waverform so that triggering of the third one-shot is an indication of a predetermined unsymmetry determined by relative values of T.sub.1 and T.sub.2 of the bipolar waveform. T.sub.3 is selected such that two symmetrical cycles of the bipolar waveform are required to clear the unsymmetry indication.

Abstract: Apparatus for measuring current over a wide range generates an eight bit accurate, 16-bit dynamic range digital signal from a current transformer secondary. Two signals proportional to the rectified secondary current, one generated by a large burden resistor and the other by an amplifier with programmable gain and an overrange indication, are applied through a multiplexer to an eight bit analog to digital converter which has three selectable reference voltages. A microprocessor selects the input signal, converter reference voltage, and one of four levels of amplifier gain which provide the greatest resolution for the magnitude of the current being measured, and provides an appropriate scale factor, from 2.sup.0 to 2.sup.8, for the eight bit accurate digital signal generated by the analog to digital converter.

Abstract: A quasi-harmonic neutralized static power converter comprises one or more threephase phase shifting transformers having open primary windings fed at opposite ends by poles in separate ones of an associated pair of six-pulse bridge inverter circuits. The secondary winding of at least one of the phase shifting transformers is a delta winding or a wye winding connected to a neutral line. In order to block zero sequence currents which would be induced in such secondaries, a zero sequence blocking transformer is inserted in either the primary of secondary of any one of the phase shifting transformers. Preferably, the zero sequence blocking transformer has three identical zero sequence blocking windings wound on a common core. Each of the zero sequence windings is connected in series with a separate one of the windings in the selected transformer primary or secondary.

Abstract: An electronic circuit arrangement for producing an output signal representative of the average value of an alternating voltage in a power transmission system, composed of: at least one circuit unit composed of a pulse width modulator (6) connected to derive, from the alternating voltage, a train of pulses modulated in width as a function of the amplitude of the alternating voltage and with a defined phase relation to the alternating voltage, an electronic circuit (4,8) connected to derive, from the alternating voltage, an alternating signal which varies in frequency with the alternating voltage and which has the defined phase relation to the alternating voltage, and a signal multiplying device (14) connected to receive the train of pulses modulated in width and the alternating signal for multiplying the pulses and the alternating signal to produce a product signal having an amplitude proportional to the average magnitude of the alternating voltage; and a signal to frequency converter (16) connected to derive

Abstract: Protective relay apparatus for providing a compensated fault impedance measurement for the determination of a better estimate of fault location along a transmission line is disclosed. In a power system network including local and remote generating sources disposed at respective ends of a transmission line segment of the transmission line, the protective relay apparatus is disposed at the local end of the line segment to measure the fault impedance for use in determining fault location. However, load flow conditions rendered by the generating sources interact with a fault which contributes resistance substantially to the fault impedance of the transmission line to cause an erroneous component in the fault impedance measurement rendering the determination of an erroneous fault location.

Abstract: A reinforced wall structure for a transformer tank characterized by a tank having opposite tank walls and braces on the walls for stiffening the walls against deflection. A transformer assembly including a transformer mounting end frame and a transformer within the end frame is mounted in the tank with the end frames adjacent to the braces so as to limit lateral movement of the assembly when an overcurrent condition occurs. A cooling fin assembly is mounted on each tank wall on the side opposite the braces.

Abstract: Loss-of-potential supervision for a distance relay controlling a circuit breaker in a poly-phase electric power transmission system is provided by blocking circuit breaker trip signals in the presence of a low voltage condition and the absence of an increase in current of more than a predetermined amount. Overblocking is prevented for weak feed conditions, a circuit breaker closing on a fault, transients induced by replacement of a fuse, and sequencing caused by tripping of a remote breaker.

Abstract: A method of stress-relief annealing a magnetic core constructed of magnetic, metallic strip material, with at least a portion of the strip material being amorphous, wherein the strip material has major plane surfaces which define first exposed surfaces of the magnetic core, and lateral edges which collectively define second exposed surfaces of the magnetic core. The method includes the step of thermally insulating the first exposed surfaces of the magnetic core, and the step of heating the magnetic core via the second exposed surfaces.

Abstract: In polyphase systems with a set of waveforms, such as a three-phase power system, each waveform is Fourier analyzed for a frequency component: A single sample/hold circuit samples each waveform sequentially, and the sampling time difference is compensated by adjusting the sampled values to a common time-point, using vector rectangular coordinate sine/cosine processing.