Resistance compensation by variable negative resistance - embodies a circuit using operational amplifier

摘要

The compensation circuit is for a resistance, notably for the contact resistance of electronic switches used in telephone exchanges. A second negative resistance (Rh) is placed between a fixed variable negative resistance (R4), (which is connected in series with the resistance (RI) to be compensated), and a current generator (OP) supplying a measuring current from which the first negative resistance (R4) is adjusted to compensate a load resistance (RI), so that for the first negative resistance (R4), the internal resistance of the current generator (OP) is transformed into negative resistance of the same value.