Battery-fed utility meter with selectable measuring characteristic

摘要

The meter has a measuring circuit with a measuring characteristic which is switched when a given threshold value (S) is reached. The circuit contains a resistance bridge with a measuring resistor (2), a reference resistor (3) and a pair of bridge resistors, threshold switches (7,8) for the measuring voltage and the reference voltage of a D-type flip-flop (9). A control logic controls a switch (1) in series with the resistance bridge, for providing a measuring current and a reference current during a measurement, with the flip-flop reset at the end of the measurement and providing an output signal when the defined threshold is exceeded for switching the measuring characteristics.