Apparatus for obtaining a mean voltage value

Abstract

Apparatus comprising a measurement-transmitting unit with two outputs to generate a time sequence of voltage values containing a measured size to be averaged; a mean value-forming unit which has two inputs connected respectively to the two outputs of the measurement-transmitting unit, and a resistor-capacitor network for continuously averaging the voltage values fed to it by the measurement-transmitting unit, the resistor-capacitor network including a capacitor which is connected across the two inputs of the mean value-forming unit via at least one resistor and at least one controllable switch; and a program-control unit connected to said at least one controllable switch and having means to control said at least one controllable switch in such a way that, during at least some of the averaging processes, the capacitor is connected to the two inputs of the mean value-forming unit, via said at least one resistor, for a switching time T.sub.i, which fulfills the condition T.sub.i =RC 1n (i/(i-.sub.1)), where i is the number of the voltage value, R is the resistance value of said at least one resistor effective when the i-th voltage value is supplied, and C is the capacitance of the capacitor. Preferably the apparatus includes two controllable switches, a second of which by-passes said at least one resistor, the program-control unit has means for closing said second of the switches to by-pass said at least one resistor when the first voltage value is supplied, and the program control unit is constructed so that it controls a first of the switches, in such a way that its switching time T.sub.i is successively shortened from the supplying of the second voltage value onwards, during a plurality of successive averaging processes.

Dependencies are inferred from the claim text.