Telephone and data overvoltage protection apparatus including a longitudinal transformer

摘要

A method and apparatus are provided for protecting a pair of telephone lines and similar data communication channels from overvoltage and transients. A filter for filtering noise and transient voltage signals above desired data signals on telephone lines and similar data communication channels includes a longitudinal transformer. The longitudinal transformer includes a single transformer core and a pair of coils. A first one of the coils is connected in series with a first telephone line or a first similar data communication channel. A second one of the coils is connected in series with a second telephone line or a second similar data communication channel. The pair of coils are substantially identical; each coil having an identical number of turns. A high impedance is provided with the longitudinal transformer to noise and transient voltage signals above desired data signals. A low impedance is provided with the longitudinal transformer to desired data signals.