Abstract: An electric watthour meter provides for selectively accumulating energy consumption in one of at least two registers according to the value of a parameter relative to a predetermined threshold level. The parameter may be a load current, a line voltage, a time of day or a combination thereof.

Abstract: A display temperature compensator employs the non linear temperature coefficient of resistance of a thermistor to non linearly vary the control voltages fed to a liquid crystal display. At low temperature, substantially the entire supply voltage is available to control the liquid crystal display segments. At higher temperatures, the thermistor contracts the range of control voltages fed to the display in order that non-selected display segments remain off. A thermistor is used which has a non linear temperature coefficient of resistance which, when combined with selected fixed resistance value, substantially compensates for the non linear threshold voltage of the liquid display.

Abstract: An electronic demand register divides a demand interval into a contiguous set of N demand subintervals. The demand in each demand subinterval is summed with the demands from the N-1 most recent contiguous demand subintervals to derive the interval demand. The interval demand is compared with a prior stored maximum demand to decide whether to discard the present interval demand or to use it to replace the previously recorded maximum demand. Demand is accumulated in terms of actual power usage by scaling power usage pulses according to the relationship in the particular meter on which the rolling demand register is used. Thresholds are provided for producing warning signals to alert the consumer to an actual or impending demand condition which may adversely affect billing.

Abstract: A watthour meter frame for an electric watthour meter includes pairs of orthogonal machined plane surfaces against which bearings are urged for accurately positioning the ends of a disk shaft of an electric watthour meter. Clearances are provided in the watthour meter frame for machining all pairs of machined surfaces without either changing the cutting tool or rotating the watthour meter frame. Worm gear bearings are similarly positioned in the watthour meter frame against three machined plane surfaces which may be machined in the same operation, and with the same cutting tool, as used in forming the pairs of machined surfaces for the disk shaft bearings. The worm gear bearings include a cylindrical barrel which is resiliently urged into contact with a pair of plane machined surfaces in a bearing well and a positioning flange having a bearing surface which is resiliently urged into a face surface surrounding the bearing well.

Abstract: A flux shunt includes a pickup plate parallel to, and closely spaced from, an outer surface of a voltage stator winding of a voltage stator for an electric meter drive apparatus. A flux-return tab of the flux shunt passes through an auxiliary coil and enters a flux-return slot in the voltage stator core of the voltage stator. The flux-return tab is biased into intimate mechanical contact with a surface of the flux-return slot both to prevent buzzing and to provide a low-reluctance return path for flux picked up by the pickup plate. The return flux, passing through the auxiliary coil induces a voltage in windings thereof for powering meter accessories such as, for example, a light-emitting diode whose illunination is indiciative of excitation of the core material of the voltage stator.

Abstract: A skid plate retained below an electronic register module includes a plurality of cantilevered spring fingers formed by parallel pairs of slots in the skid plate. Each cantilevered spring finger includes a frusto-conical button which bears against a back plate in a housing during installation of the electronic register module therein. A rear end of the back plate includes a pair of mouse holes into which a rear pair of frusto-conical buttons engage during an intermediate stage of inserting the electronic register module into the housing. This engagement establishes the correct side-to-side positioning of the rear end of the electronic register module. A front cantilevered spring finger and its associated frusto-conical button resiliently urge the front of the electronic register module upward during substantially all stages of installation and in the operational position thereof.

Abstract: An electronic demand register for an electric meter includes a plurality of pushbutton controls for controlling material displayed or a mode of operation of the demand register. A lockable switch actuator includes an actuating paddle within a cover or housing of the meter which, when unlocked, can be rotated into alignment with a selected one of the pushbutton controls and then pushed inward to actuate the selected pushbutton control. A pair of bosses bracketing one of the pushbutton controls prevents actuation of its respective control until the actuating paddle is accurately positioned between them. A second pair of bosses bracketing another of the pushbutton controls are spaced too closely apart to permit the actuating paddle to pass therebetween and they thus prevent actuation of their respective pushbutton control.

Abstract: An electronic demand register performs rolling demand metering in which a demand interval is divided into N subintervals. At the end of each subinterval, the demand data from the just-completed subinterval is summed with the demand in the most-recent N-1 contiguous subintervals to derive an interval demand. A test operation is provided in which the stored maximum demand, a number representing the remainder of the subinterval interrupted by the test and programmed constants are stored in non-volatile memory but are also retained in the processor for use during test. A test reset switch resets accumulated demand data and presets the subinterval timer to predetermined values from which they may be operated by a calibrated test load to confirm the performance of the demand register. At the end of testing, all data in the processor is zeroed and the data stored in non-volatile memory is restored.

Abstract: An electronic demand register performs rolling demand metering in which a demand interval is divided into N subintervals. At the end of each subinterval, the demand data from the just-completed subinterval is summed with the demand in the most-recent N-1 contiguous subintervals to derive an interval demand. In the event of a power outage, the existing value of maximum demand, and a number representing the time remaining in the subinterval interrupted by the power outage, as well as programmed constants, are stored in non-volatile memory for safekeeping during the power outage. After power is restored, the stored values are used to preset a maximum demand storage to the saved value of maximum demand and to preset a subinterval timing down counter to the value it had upon the detection of an impending power outage. A logic circuit freezes accumulation of demand data for a grace period following power restoration to avoid detection of an artificially high demand from synchronized starting loads.

Abstract: An electronic register for an electric meter includes a non-volatile storage into which data is written upon the detection of an impending power outage. A sufficient quantity of electric energy is normally stored in a capacitor to continue operation of the electronic register for a long enough period of time to complete the writing of data to the non-volatile storage. In order to prevent writing of the data to non-volatile storage in the presence of noise or momentary power outages, when the voltage in the capacitor decays to a point which indicates an impending power outage, a timer is started. If the voltage is not restored before the end of the timing cycle of the timer, then the data is written to the non-volatile storage. If the voltage is restored before the end of the timing cycle, then writing of the data to the non-volatile storage is prevented.

Abstract: An electronic demand register for an electric meter includes a volatile storage for normal processing of data and a non-volatile storage into which data is serially written upon the occurrence of conditions which may threaten the integrity of such data and from which the data is again retrieved when the condition no longer exists. The data formats for transmission of the data to the non-volatile memory and for receiving it therefrom do not agree with the data formats which the volatile storage must have. A communications buffer assembles a data package for transmission to the non-volatile memory which has a format which can be suitably serially transmitted to the non-volatile memory and be properly interpreted there due to the manner in which the non-volatile memory recognizes and stores data.

Abstract: A reset mechanism for a cyclometer register employs teeth formed on an axially resiliently urged shaft to engage abutments formed on cyclometer drums to permit resetting of the cyclometer drums. The teeth are normally maintained out of alignment with the abutments by resilient urging of a spring and are manually displaced into engagement for resetting. Carry pinions on a pinion shaft are urged into mesh with respective gearwheels on the cyclometer drums by a pair of springs. During resetting, the pinion shaft, with its pinions, is displaced outward. When the pinions are displaced outward, one or more teeth on each pinion enter a window disposed adjacent thereto in the frame of the cyclometer register. The windows lock the pinions into a predetermined angular position which enables proper mesh to be made with the gearwheels at the conclusion of the resetting operation when the springs again urge the pinions into meshed engagement.

Abstract: An electronic demand register includes a processor for calculating a demand in a demand subinterval. At the end of each demand subinterval, the calculated demand is summed with the demand in the preceding N-1 subintervals to derive an interval demand over N contiguous subintervals. The interval demand is compared to a previously recorded maximum demand and, if the interval demand exceeds the maximum demand, its value is substituted for the maximum demand for use in subsequent comparisons. The processor employs volatile memory. A non-volatile memory is provided for storing the billing data and programmed constants in the event of an impending power outage. A power monitor detects the possibility of an impending power outage and, operating on stored energy, both enables and powers the transfer of data to the non-volatile memory. When power is resumed, the power monitor enables resetting the processor and retransferring the data from the non-volatile to the volatile memory for resumption of demand metering.

Abstract: An electronic solid state Q-hour meter for measuring leading and lagging VARS quantities of electric power over a defined range of power factor. The Q-hour meter comprises first and second time division/pulse width-amplitude modulated/analog multiplier circuits. First and second current transformers are coupled to first and second phases of a multi-phase power supply to be monitored for deriving first and second analog circuit indicating signals which are supplied to respective analog current input terminals of the analog multipliers. First and second potential transformers are coupled across the first and second phases of the multi-phase power supply for deriving first and second analog voltage indicating signals that are supplied to respective input terminals of the first and second analog multiplier circuits.

Abstract: A flip-over mechanism for a cyclometer register includes an eccentrically balanced fly-wheel freely rotatable on a drum shaft between a driver drum and a first driven drum, each drum being marked with decimal digits 0-9. The driver drum is driven in smooth rotation by a measuring device whose measurements are to be accumulated. At a certain point in its rotation, the driver drum engages and begins rotating the fly-wheel. As the driver drum is rotated into a position at which it performs a 9-to-0 transition, the fly-wheel becomes overbalanced and rotates forward on its stored potential energy until a striker thereon engages a tooth of a first carry pinion located between the fly-wheel and the first driven drum. This applies a momentary forward tap to the first carry pinion. The tap on the carry pinion provides a substantially instantaneous carry operation to be performed in all of the driven drums which are in position to require a carry.

Abstract: A light load adjustment for an electric meter includes a frame attachable to a core of a voltage coil and a pole-shading element slideable with respect to the frame. The pole-shading element includes a windowed plate or a pair of tabs interposeable between the core of the voltage coil and the rotatable disk and effective to change the direction and magnitude of the torque applied to the rotatable disk of the electric meter at light load. A single adjusting screw for the light load adjustment is placed in one of its two alternative positions. In either of its two alternative positions, rotation of the head of the adjusting screw by a worker facing the head produces a displacement of the windowed plate or tabs which tends to change the disk speed in a sense which is consistent with the convention for the relationship between the direction of rotation of an adjustment and the change in disk speed.

Abstract: A display controller drives a nine digit, seven segment display in accordance with desired display formats for preselected lengths of time. The controller accepts control commands and data by means of a serial three wire asynchronous link. The display controller includes the capability for receiving binary data and converting it to binary coded decimal data for subsequent display and further includes the capability for scaling data as well as performing self tests to insure that the display is functioning correctly following a power outage.

Abstract: An improved solid state semiconductor integrated circuit electronic watt/watthour meter circuit having analog and high frequency digital outputs with automatic error correction. The meter comprises first and second transformers for developing first and second voltage and current indicating signals for supply to a multiplier circuit that multiplies the two signals together and derives an output analog product signal representative of the instantaneous power being supplied by a source of electric energy. A multiplier low pass filter circuit is coupled to the output from the multiplier circuit for deriving from the product signal an average value power signal V. An analog-to-pulse rate converter is supplied with the average value power signal V and serves to convert it into a high frequency train of output signal pulses wherein each output signal pulse represents a predetermined quantized amount of electric energy.

Abstract: An electronic watt and kilowatt hour measuring circuit susceptible of being fabricated for the most part in solid state semiconductor monolithic integrated circuit form is provided. The electronic measuring circuit uses an active load terminated current transformer sensor for sensing alternating load current and a voltage transformer for sensing the alternating current voltage supplied from a source of alternating current electric energy being monitored. The output of the active load terminated current sensor transformer has an inherent DC-offset error voltage added to the alternating voltage which is proportional to the current being measured. This DC-offset error voltage is caused by the operational amplifier employed in the active load terminated current transformer sensor.

Abstract: Disclosed is a meter cover (housing) mounted receptacle and detachable magnetic coupler incorporating optical communication devices for electronically communicating with electronic circuitry housed within the meter cover.