Variable delay equaliser in form of bridged T - has negative immitance converter in shunt with arm operational amplifier, shunted by resistor

摘要

The equaliser has a differential coil in the series arms, and a resistor in the shunt arm between the coil tapping and the earth wire. An LC resonant circuit is in the bridge arm. The resistor is replaced by an operational amplifier (OP) in a negative immitance converter (IN). The amplifier (OP) inverting input is connected through a capacitor (C2) and a resistor (R1) to its output and earth wire (1) respectively. Its non-inverting input is connected through a variable capacitor (C1) to its output and directly to the coil (DL) tapping. A resistor (R2) is between the coil (DL) tapping and earth wire (1).