RINGING APPLICATION CIRCUIT

摘要

RINGING APPLICATION CIRCUIT This invention relates to line circuits and, in particular, to the apparatus contained therein for switching the ringing signal on to the communication pair which connects the line circuit to the telephone station set which it serves. Electromechanical relays provide an ideal switching function but require a significant amount of space while semiconductor switches do not require much space but provide an imperfect switching function which adversely affects the performance characteristics of the line circuit. The subject ringing apparatus makes use of a semiconductor switch to provide the ring relay function and incorporates additional circuitry to eliminate the difficulties associated with semiconductor switches. (FIG. 1).