Compensated input filter - is loss and temperature compensated for receivers in AF power line carrier control systems

摘要

The input filter comprises at least one LC element, consisting of a coil or transformer and a capacitor; a feedback resistor; an amplifier; over-all attenuation resistor and a balancing network. The feedback resistor is temperature sensitive in the same way as the coil resistance. The amplifier gain can be adjusted to one plus the quotient of coil resistance divided by the feedback resistance. The amplifier input is parallel to the feedback resistor. The balancing network is in the form of a resistor bridge consisting of two fixed resistors in series, with a potentiometer in parallel, and a diagonal resistor between the junction point of the fixed resistors and the potentiometer wiper.