Error compensating circuitry for electronic electricity meter - has ohmic resistor and capacitor in series between common pole of changeover switch and phase lead of mains

摘要

The electronic switch of the time-division-multiplier used in the electricity meter is in the form of a change-over switch (7) in order to halve the offset voltage of the integrator (8) and eliminate the errors arising from the voltage-dependent resistors of the switching elements. The working contact of the switch (7) couples the electrical mains values to be modulated with the inverting input of the operational amplifier (10) of the integrator. The lazy contact couples the electrical values to appts. earth. An ohmic resistor (5) and capacitor (6) are connected between the change-over switch pole and the phase lead (L) of the mains. The value of the resistor is large compared with the a.c. impedance of the capacitor at mains frequency. USE/ADVANTAGE - Domestic meter. Sufficient compensation for measuring errors arising from various causes.