Showing papers on "Electricity meter published in 1979"

Multi-function A.C. power meter

Abstract: A multi-function alternating current meter having a voltage probe and clamp type current probe for sampling voltage and current of a alternating current line without physically breaking into the line Components include the two input probes which are connected to a squaring circuit and compensated low pass active filters which are arranged for feeding the respective output signals into an analog summing amplifier Subsequently the signals are fed into a calibrated output indicator A scaled multiplier and phase lead/lag detector are included in the circuit Switches are capable of rerouting the input signals through various components, and the various outputs are individually applied to the calibrated output indicator to indicate the AC line's power factor, phase angle, true power, apparent power, voltage, current, or lead/lag status, as selected

Electricity meter installation method - has contact pins inserted into guide-member to help locate meter perpendicular to long axes of contact pins

Abstract: The electricity meter installation procedure and use age method is designed to avoid labour and time wasting durinstallation, and during exchange, of the meter. Thus, with a meter having its input and output formed by contact pins, the later are inserted into a guide member which helps to locate the meer perpendicularly to the longitudinal axes of the contact pins by moving the meter into slots provided in counter (adjacent) contact pieces. The latter have terminals for the incoming leads from the supply mains and for the leads running to the consumer installation.

Active power meter with nonlinear stochastic coding - uses noise source, D=A converter and stochastic decoding in controllable counter-frequency divider

Abstract: The electricity meter consists of a non-linear noise source with constant probability p = 0.5 which produces a noise voltage (UR) whose partition function approaches that of a non-linear function with the aid of shift-registers and d-a converters. This noise voltage is compared (8) with the voltage and current and the voltage and current are converted into stochastic pulses with a pulse probability proportional to the linear segments of the characteristic used for the conversion. By the use of logic gates (9, 10) multiplication is carried out. Stochastic decoding is done in a controllable counter-frequency-divider (11) whose division ratio is determined by the respective characteristic segment being used.

Monitor for electricity meter with static measurement unit - delivers reference signals of desired amplitude and frequency to multiplier circuit supplying comparator

Abstract: A monitor circuit for an electricity meter with static or electronic measurement unit contg. an analogue voltage multiplication circuit is designed to detect indication errors caused by errors in component parts. This is achieved with low production and installation costs. The monitor circuit delivers reference signals of defined amplitude and frequency to the multiplier circuit. The product is fed to a reference signal comparator circuit with another input from a test signal generator providing a desired value signal. The comparator output adjusts the mechanical indicator mechanism via a stepper motor to correct for errors.

Error analysis in the measurement of average power with application to switching controllers

Abstract: Power measurement errors due to the bandwidth of a power meter and the sampling of the input voltage and current of a power meter were investigated assuming sinusoidal excitation and periodic signals generated by a model of a simple chopper system. Errors incurred in measuring power using a microcomputer with limited data storage were also considered. The behavior of the power measurement error due to the frequency responses of first order transfer functions between the input sinusoidal voltage, input sinusoidal current, and the signal multiplier was studied. Results indicate that this power measurement error can be minimized if the frequency responses of the first order transfer functions are identical. The power error analysis was extended to include the power measurement error for a model of a simple chopper system with a power source and an ideal shunt motor acting as an electrical load for the chopper. The behavior of the power measurement error was determined as a function of the chopper's duty cycle and back EMF of the shunt motor. Results indicate that the error is large when the duty cycle or back EMF is small. Theoretical and experimental results indicate that the power measurement error due to sampling of sinusoidal voltages and currents becomes excessively large when the number of observation periods approaches one-half the size of the microcomputer data memory allocated to the storage of either the input sinusoidal voltage or current.

A Simple Power Meter for Measuring Outputs from a High Power Continuous Wave (CW) CO2 Laser

Abstract: The design of a power meter for measuring continuous wave (CW) outputs is presented. The principle of the operation is to measure the temperature rise at the surface of an aluminum slab that absorbs the energy of the incident 10.6 micron radiation. In order to make effective absorption, the surface is covered with a layer of Al203 of a few microns in thickness. Linear response to the incident power up to 200 W and allowable power density of more than 500 W/cm2 are attained.