BATTERY FEEDING CIRCUIT FOR EXCHANGES

摘要

A reference resistance is connected to each of the two inputs. AC and DC feedback are fed back to the two inputs with coupling capacitors via reference resistors and provide a desired AC terminating resistance and DC input resistance. A control signal reverses the polarity of signals to the inputs by a noiseless signal to the DC feedback. The AC signal on the input is differentially amplified so that the differential signal is distinguished from the unwanted common mode signal. The terminating resistance for each signal can be changed by altering the feedback ratios of the feeding resistor between both signals.