Siemens Aktiengesellschaft

Manfred Schwendtner

Gunter Steinmuller

Klaus Windsheimer

Julius Brunner

Wolfgang Dohmstreich

Rudolf Seibert

Walther Scharm

Rainer Forthner

Karlheinz Kutschera

Gunter Haefele

An electricity meter with differentiating input converters, in particular current converters, attains improved signal processing by providing a respective analog filter, in particular a low-pass filter, following each of the input converters. In this way, voltage peaks are limited for electronics downstream. Adulteration of measured signals caused by filters is compensated for by a digital filter in a downstream signal processing.

Electricity meter

The current transformer of an electronic house-service meter has a ferromagnetic core which, except for an air gap, is closed. A measuring coil is inserted in the air gap and is fastened, and dimensioned so that it lies within the cross sectional area of the core.

Current-voltage transformer for electronic house-service meter

An arrangement for introducing audio-frequency signals into a power supply line containing a compensating capacitor, through a junction converter having primary winding which is connected with an audio-frequency signal generator. The secondary winding of the junction converter is connected in series with the compensating capacitors which are not located in a parallel branch line to the secondary winding of the junction converter, and thus do not represent a load on the audio-frequency signal. The audio-frequency signal is coupled into the power supply line through the compensating capacitors which are connected in series with the secondary winding, whereby the coupling in is effected, on the one hand, through one and, on the other hand, through two parallel-connected compensating capacitors.

Arrangement for introducing audio-frequency signals into a power supply

An electronic arrangement for determination of reactive power, including two transducers delivering at their outputs measuring voltages proportional to supply current and supply voltage. An additional phase shift of 90.degree. between the two measuring voltages is produced by phase-shifting elements. A signal proportional to reactive power is produced in a following multiplier element. To preclude as far as possible variation of amplitude and phase shift occurring on frequency fluctuation in a frequency range close to rated frequency of the power supply, an all-pass is connected as a phase-shifting element ahead of each of the two respective inputs of the multiplier element whereby one all-pass is designed to produce a phase shift of +45.degree. and the other all-pass is designed to produce a phase shift of -45.degree. at the rated frequency of the power supply.

Electronic arrangement for determination of reactive power

This invention is an electronic kilowatthour meter with a time-division multiplier, wherein a proportional first current is derived from the load voltage without a voltage transformer and a proportional second current is derived by means of an inverting amplifier, with a polarity opposite to that of the first current and instantaneous values halved as compared to the first current, and that the first current is added to the second current in one of two switching conditions by means of a switch which is operated by a pulse width-frequency modulator controlled by the load current, so that the average value of the sum current is proportional to the product of the load current and the load voltage.

Growing community of inventors

Schwarzenbruck, Germany

Manfred Schwendtner