ELECTRONIC ENERGY CONSUMPTION METER AND METHOD FOR MEASURING ELECTRICAL ENERGY WITH AN ENERGY CONSUMPTION COUNTER

摘要

1. Electronic energy consumption meter with a device for generating a voltage signal (Vu ) proportional to the user voltage, a first intermediate store (2) to which the voltage signal (Vu ) is fed, a device (4) for generating a voltage signal (Vi ) proportional to the user current, a second intermediate store (7) to which the voltage signal (Vi ) is fed, an analogue digital converter (A/D converter) (11) and a circuit (9) which feeds the sample values (Vu , Vi ) present at the output of the intermediate store (2, 7) with a given sampling frequency alternately to the A/D converter (11), which then sequentially feeds them in digitised form to a microprocessor (13) for further processing, wherein the device for generating a voltage signal (Vi ) proportional to the current use is a shunt resistance or shunt (3) between phase entry and exit, wherein the phase entry is connected with the first input of an operational amplifier (6) and has a measuring resistance (5) which is connected between the phase output and the second input of the operational amplifier (6) and that voltage signals (Vi ) proportional to the user current are taken off at the output of the operational amplifier (6), characterised in that the shunt resistance (3) and the measuring resistance (5) are coupled with one another thermally closely so that the measuring resistance (5) on temperature changes in percentage terms evenly as does the shunt resistance (3) and thus a temperature compensated voltage signal (Vi ) is provided at the output of the operational amplifier.