TELEPHONE STATION MAKE-BUSY CIRCUIT

摘要

TELEPHONE STATION MAKE-BUSY CIRCUIT A telephone central office trunk utilized for establishing connections of calling telephone station lines with a called telephone station line is arranged to enable a subscriber to make a called telephone station appear busy to incoming calls. The trunk is provided with apparatus arranged to respond to the momentarily appearance of a low impedance across the called telephone station line in response to ringing signals applied thereto by opening the established connections and applying busy tone to the calling telephone station lines.