Comparator circuit comparing signal voltage with reference voltage

摘要

The comparator circuit has an element (1) for comparing at least one signal voltage (US) with a reference voltage (Ur). The signal voltage is applied at a second input (1b). A circuit arrangement (2-7) is provided, which forms an average value of the signal voltage (US), and the formed average value is applied as a reference voltage (Ur) at the first input (1a) of the comparator element (1). A first diode (6) and a second diode (7) have a common connection point, which is fed with the signal input (18) via a series resistance (8). The first diode cathode has a connection of a 1st capacitor (4) and the second diode anode has a connection to a 2nd capacitor (5). The full wave rectified version of the input signal is then applied across a voltage divider (2,3). The 2nd connection of the 1st capacitor with the circuit earth and the 2nd connection fo the 2nd capacitor is connected with a voltage, which is larger than the minimum value of the signal voltage (US).